vc/google/chromeos: Always use CHROMEOS_RAMOOPS_DYNAMIC

Always allocate RAMOOPS from CBMEM and drop the related
static variable CHROMEOS_RAMOOPS_RAM_START.

Change-Id: Icfcf2991cb78cc6e9becba14cac77a04d8ada56a
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/50608
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/soc/intel/alderlake/Kconfig

@@ -213,9 +213,6 @@ config SOC_INTEL_COMMON_LPSS_UART_CLK_N_VAL
 	hex
 	default 0x7fff
 
-config CHROMEOS
-	select CHROMEOS_RAMOOPS_DYNAMIC
-
 config VBOOT
 	select VBOOT_SEPARATE_VERSTAGE
 	select VBOOT_MUST_REQUEST_DISPLAY