soc/intel/broadwell: Use C_ENVIRONMENT_BOOTBLOCK

This puts the cache-as-ram init in the bootblock.
Before setting up cache as ram the microcode updates are applied.

This removes the possibility for a normal/fallback setup although
implementing this should be quite easy.

Setting up LPC in the bootblock to output console on SuperIOs is not
done in this patch, therefore BOOTBLOCK_CONSOLE is not yet selected.

Change-Id: I44eb6d380dea5b82e3f009a46381a0f611bb7935
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Signed-off-by: Matt DeVillier <matt.devillier@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/30383
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>
diff --git a/src/soc/intel/broadwell/bootblock/systemagent.c b/src/soc/intel/broadwell/bootblock/systemagent.c
index e618636..7aaed78 100644
--- a/src/soc/intel/broadwell/bootblock/systemagent.c
+++ b/src/soc/intel/broadwell/bootblock/systemagent.c
@@ -16,8 +16,9 @@
 #include <device/pci_ops.h>
 #include <soc/pci_devs.h>
 #include <soc/systemagent.h>
+#include <cpu/intel/car/bootblock.h>
 
-static void bootblock_northbridge_init(void)
+void bootblock_early_northbridge_init(void)
 {
 	uint32_t reg;