soc/intel/xeon_sp/cpx/Kconfig: Relocate 'select CACHE_MRC_SETTINGS'

This will remove the warning:
 "src/soc/intel/xeon_sp/cpx/Kconfig:79:warning: config symbol 'CPU_BCLK_MHZ' uses select, but is not boolean or tristate"

Change-Id: I2cfaf347b638e3847caa167e7efda89e9202960a
Signed-off-by: Elyes HAOUAS <ehaouas@noos.fr>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/44548
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Benjamin Doron <benjamin.doron00@gmail.com>
Reviewed-by: Nico Huber <nico.h@gmx.de>
Reviewed-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: Jonathan Zhang <jonzhang@fb.com>

src/soc/intel/xeon_sp/Kconfig

@@ -17,6 +17,7 @@ config SOC_INTEL_COOPERLAKE_SP
 	bool
 	select XEON_SP_COMMON_BASE
 	select PLATFORM_USES_FSP2_2
+	select CACHE_MRC_SETTINGS
 	help
 	  Intel Cooperlake-SP support
 

src/soc/intel/xeon_sp/cpx/Kconfig

@@ -76,8 +76,6 @@ config CPU_BCLK_MHZ
 	int
 	default 100
 
-select CACHE_MRC_SETTINGS
-
 # CPX-SP has 2 IMCs, 3 channels per IMC, 2 DIMMs per channel
 # Default value is set to one socket, full config.
 config DIMM_MAX