src: Remove unneeded include <cbmem.h>

Change-Id: I89e03b6def5c78415bf73baba55941953a70d8de
Signed-off-by: Elyes HAOUAS <ehaouas@noos.fr>
Reviewed-on: https://review.coreboot.org/29302
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/soc/intel/broadwell/systemagent.c

@@ -24,7 +24,6 @@
 #include <device/pci_ids.h>
 #include <stdlib.h>
 #include <string.h>
-#include <cbmem.h>
 #include <vendorcode/google/chromeos/chromeos.h>
 #include <soc/cpu.h>
 #include <soc/iomap.h>