soc/intel/quark/memmap: Add missing 'include <cpu/x86/mtrr.h>'

Change-Id: I6a066659758aeb0251d9b37f525ad987b90832db
Signed-off-by: Elyes HAOUAS <ehaouas@noos.fr>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/41787
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/soc/intel/quark/memmap.c

@@ -2,6 +2,7 @@
 
 #include <arch/romstage.h>
 #include <cbmem.h>
+#include <cpu/x86/mtrr.h>
 #include <soc/reg_access.h>
 
 void fill_postcar_frame(struct postcar_frame *pcf)