BX301A01B-SW-99002-r29p0-01eac0.tar mali driver compilation. Error "undefined reference to `platform_funcs'"

Hi all.

I'm trying to build BX301A01B-SW-99002-r29p0-01eac0.tar driver with linux kernel and i have some doubts.

First of all, i'm trying to build this driver for a GPU Mali-G31 MP2. Is this driver compatible for this GPU? I have seen that this GPU uses Bifrost driver but in the package i only see code for Midgard driver. Is Midgard now compatible with Mali-G31? I got this driver from Bifrost driver download page.

My second question is about compilation proccess. I have copied the content of the tarball to its corresponding directories and i have enabled CONFIG_MALI_MIDGARD in menuconfig y i have left the default configuration. 

The proccess compilation fails with the next output

  CC      init/version.o
  LD      init/built-in.o
drivers/built-in.o: In function `kbasep_platform_device_init':
/home/goonie/odroidgo/kernel/linux/drivers/gpu/arm/midgard/mali_kbase_config.c:33: undefined reference to `platform_funcs'
/home/goonie/odroidgo/kernel/linux/drivers/gpu/arm/midgard/mali_kbase_config.c:33:(.text+0xf73e4): relocation truncated to fit: R_AARCH64_ADR_PREL_PG_HI21 against undefined symbol `platform_funcs'
/home/goonie/odroidgo/kernel/linux/drivers/gpu/arm/midgard/mali_kbase_config.c:33: undefined reference to `platform_funcs'
/home/goonie/odroidgo/kernel/linux/drivers/gpu/arm/midgard/mali_kbase_config.c:33: undefined reference to `platform_funcs'
drivers/built-in.o: In function `kbasep_platform_device_term':
/home/goonie/odroidgo/kernel/linux/drivers/gpu/arm/midgard/mali_kbase_config.c:44: undefined reference to `platform_funcs'
/home/goonie/odroidgo/kernel/linux/drivers/gpu/arm/midgard/mali_kbase_config.c:44:(.text+0xf742c): relocation truncated to fit: R_AARCH64_ADR_PREL_PG_HI21 against undefined symbol `platform_funcs'
/home/goonie/odroidgo/kernel/linux/drivers/gpu/arm/midgard/mali_kbase_config.c:44: undefined reference to `platform_funcs'
drivers/built-in.o: In function `kbase_pm_runtime_init':
/home/goonie/odroidgo/kernel/linux/drivers/gpu/arm/midgard/backend/gpu/mali_kbase_pm_backend.c:53: undefined reference to `pm_callbacks'
/home/goonie/odroidgo/kernel/linux/drivers/gpu/arm/midgard/backend/gpu/mali_kbase_pm_backend.c:53:(.text+0x1248c8): relocation truncated to fit: R_AARCH64_ADR_PREL_PG_HI21 against undefined symbol `pm_callbacks'
/home/goonie/odroidgo/kernel/linux/drivers/gpu/arm/midgard/backend/gpu/mali_kbase_pm_backend.c:53: undefined reference to `pm_callbacks'
/home/goonie/odroidgo/kernel/linux/drivers/gpu/arm/midgard/backend/gpu/mali_kbase_pm_backend.c:56: undefined reference to `pm_callbacks'
drivers/built-in.o: In function `kbase_pm_register_access_enable':
/home/goonie/odroidgo/kernel/linux/drivers/gpu/arm/midgard/backend/gpu/mali_kbase_pm_backend.c:108: undefined reference to `pm_callbacks'
/home/goonie/odroidgo/kernel/linux/drivers/gpu/arm/midgard/backend/gpu/mali_kbase_pm_backend.c:108:(.text+0x1249a8): relocation truncated to fit: R_AARCH64_ADR_PREL_PG_HI21 against undefined symbol `pm_callbacks'
/home/goonie/odroidgo/kernel/linux/drivers/gpu/arm/midgard/backend/gpu/mali_kbase_pm_backend.c:108: undefined reference to `pm_callbacks'
drivers/built-in.o:/home/goonie/odroidgo/kernel/linux/drivers/gpu/arm/midgard/backend/gpu/mali_kbase_pm_backend.c:125: more undefined references to `pm_callbacks' follow
drivers/built-in.o: In function `kbase_pm_register_access_disable':
/home/goonie/odroidgo/kernel/linux/drivers/gpu/arm/midgard/backend/gpu/mali_kbase_pm_backend.c:125:(.text+0x1249ec): relocation truncated to fit: R_AARCH64_ADR_PREL_PG_HI21 against undefined symbol `pm_callbacks'
make: *** [Makefile:1022: vmlinux] Error 1

It looks like midgard/platform/rk is has not been compiled but it is defined in the config page

There is something that i'm doing wrong?

Regards.
José Antonio