Drop superfluous C_ENVIRONMENT_BOOTBLOCK checks

Some guarding is not needed because the linker drops the code,
other guarding is not needed because all platforms using the code now
have C_ENVIRONMENT_BOOTBLOCK.

Change-Id: I3b1a94e709aa291e1156c854874d7bf461981f32
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/37157
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: HAOUAS Elyes <ehaouas@noos.fr>
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>

src/mainboard/facebook/fbg1701/Makefile.inc

@@ -16,13 +16,13 @@
 ##
 
 ifneq ($(filter y,$(CONFIG_VENDORCODE_ELTAN_VBOOT) $(CONFIG_VENDORCODE_ELTAN_MBOOT)),)
-bootblock-$(CONFIG_C_ENVIRONMENT_BOOTBLOCK) += board_verified_boot.c
+bootblock-y += board_verified_boot.c
 postcar-y += board_verified_boot.c
 ramstage-y += board_verified_boot.c
 romstage-y += board_verified_boot.c
 endif
 
-bootblock-$(CONFIG_C_ENVIRONMENT_BOOTBLOCK) += com_init.c
+bootblock-y += com_init.c
 
 ramstage-y += cpld.c
 ramstage-y += gpio.c

src/mainboard/portwell/m107/Makefile.inc

@@ -15,7 +15,7 @@
 ## GNU General Public License for more details.
 ##
 
-bootblock-$(CONFIG_C_ENVIRONMENT_BOOTBLOCK) += com_init.c
+bootblock-y += com_init.c
 
 ramstage-y += gpio.c
 ramstage-y += hda_verb.c