Kconfig: Drop the C_ENVIRONMENT_BOOTBLOCK symbol

The romcc bootblock will be deprecated soon and most platforms use
C_ENVIRONMENT_BOOTBLOCK already. This patch drops the
CONFIG_C_ENVIRONMENT_BOOTBLOCK symbol and adds CONFIG_ROMCC_BOOTBLOCK
where needed.

Change-Id: I773a76aade623303b7cd95ebe9b0411e5a7ecbaf
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/37154
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: HAOUAS Elyes <ehaouas@noos.fr>
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-by: Michał Żygowski <michal.zygowski@3mdeb.com>

src/cpu/qemu-x86/Kconfig

@@ -21,5 +21,4 @@ config CPU_QEMU_X86
 	select UDELAY_TSC
 	select TSC_MONOTONIC_TIMER
 	select UNKNOWN_TSC_RATE
-	select C_ENVIRONMENT_BOOTBLOCK
 	select SMM_ASEG