nvmem: stm32: fix OPTEE dependency

The stm32 nvmem driver fails to link as built-in when OPTEE
is a loadable module:

aarch64-linux-ld: drivers/nvmem/stm32-bsec-optee-ta.o: in function `stm32_bsec:
stm32-bsec-optee-ta.c:(.text+0xc8): undefined reference to `tee_client_open_session'
aarch64-linux-ld: drivers/nvmem/stm32-bsec-optee-ta.o: in function `stm32_bsec:
stm32-bsec-optee-ta.c:(.text+0x1fc): undefined reference to `tee_client_open_context'

Change the CONFIG_NVMEM_STM32_ROMEM definition so it can only
be built-in if OPTEE is either built-in or disabled, and
make NVMEM_STM32_BSEC_OPTEE_TA a hidden symbol instead.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20230206134356.839737-23-srinivas.kandagatla@linaro.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/nvmem/Kconfig

@@ -291,8 +291,7 @@ config NVMEM_SPRD_EFUSE
 	  will be called nvmem-sprd-efuse.
 
 config NVMEM_STM32_BSEC_OPTEE_TA
-	bool "STM32MP BSEC OP-TEE TA support for nvmem-stm32-romem driver"
-	depends on OPTEE
+	def_bool NVMEM_STM32_ROMEM && OPTEE
 	help
 	  Say y here to enable the accesses to STM32MP SoC OTPs by the OP-TEE
 	  trusted application STM32MP BSEC.
@@ -303,7 +302,7 @@ config NVMEM_STM32_BSEC_OPTEE_TA
 config NVMEM_STM32_ROMEM
 	tristate "STMicroelectronics STM32 factory-programmed memory support"
 	depends on ARCH_STM32 || COMPILE_TEST
-	imply NVMEM_STM32_BSEC_OPTEE_TA
+	depends on OPTEE || !OPTEE
 	help
 	  Say y here to enable read-only access for STMicroelectronics STM32
 	  factory-programmed memory area.