soc/amd: factor out common SMM relocation code

The common code gets moved to soc/amd/common/block/cpu/smm, since it is
related to the CPU cores and soc/amd/common/block/smi is about the SMI/
SCI functionality in the FCH part. Also relocation_handler gets renamed
to smm_relocation_handler to keep it clear what it does, since it got
moved to another compilation unit.

Signed-off-by: Felix Held <felix-coreboot@felixheld.de>
Change-Id: I45224131dfd52247018c5ca19cb37c44062b03eb
Reviewed-on: https://review.coreboot.org/c/coreboot/+/50462
Reviewed-by: Raul Rangel <rrangel@chromium.org>
Reviewed-by: Marshall Dawson <marshalldawson3rd@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/soc/amd/picasso/Kconfig

@@ -42,6 +42,7 @@ config CPU_SPECIFIC_OPTIONS
 	select SOC_AMD_COMMON_BLOCK_SATA
 	select SOC_AMD_COMMON_BLOCK_SMBUS
 	select SOC_AMD_COMMON_BLOCK_SMI
+	select SOC_AMD_COMMON_BLOCK_SMM
 	select SOC_AMD_COMMON_BLOCK_SMU
 	select SOC_AMD_COMMON_BLOCK_SPI
 	select SOC_AMD_COMMON_BLOCK_TSC_FAM17H_19H