soc/amd/cezanne: select RTC

The RTC functionality will be used by elog.

Change-Id: I3a8d0a353620f64207d5ba8e17c145090f0c7506
Signed-off-by: Felix Held <felix-coreboot@felixheld.de>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/50543
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Marshall Dawson <marshalldawson3rd@gmail.com>

src/soc/amd/cezanne/Kconfig

@@ -22,6 +22,7 @@ config SOC_SPECIFIC_OPTIONS
 	select IOAPIC
 	select PLATFORM_USES_FSP2_0
 	select RESET_VECTOR_IN_RAM
+	select RTC
 	select SOC_AMD_COMMON
 	select SOC_AMD_COMMON_BLOCK_ACPI
 	select SOC_AMD_COMMON_BLOCK_ACPIMMIO