armv7: set cache level explicitly for dcache/unified cache case

This adds a missing CSSELR write in the case of a dcache or unified
cache being invalidated by armv7_invalidate_caches(), ensuring that
all levels of dcache/unified cache are invalidated as expected when
the function is called.

Change-Id: Ie90184bf8a8181afa3afe0786897455b30b7f022
Signed-off-by: David Hendricks <dhendrix@chromium.org>
Reviewed-on: http://review.coreboot.org/2947
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
Tested-by: build bot (Jenkins)

src/arch/armv7/lib/cache.c

@@ -310,6 +310,8 @@ void armv7_invalidate_caches(void)
 		case 0x2:
 		case 0x4:
 			/* dcache only or unified cache */
+			csselr = level << 1;
+			write_csselr(csselr);
 			dcache_invalidate_all();
 			break;
 		case 0x3: