CBMEM: Always use DYNAMIC_CBMEM

Drop the implementation of statically allocated high memory
region for CBMEM. There is no longer the need to explicitly
select DYNAMIC_CBMEM, it is the only remaining choice.

Change-Id: Iadf6f27a134e05daa1038646d0b4e0b8f9f0587a
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: http://review.coreboot.org/7851
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@google.com>

src/cpu/intel/fsp_model_206ax/Kconfig

@@ -42,7 +42,6 @@ config CPU_SPECIFIC_OPTIONS
 	select TSC_SYNC_MFENCE
 	select LAPIC_MONOTONIC_TIMER
 	select BROKEN_CAR_MIGRATE
-	select DYNAMIC_CBMEM
 
 config BOOTBLOCK_CPU_INIT
 	string