vboot: include vb2_sha.h when required

Should include vb2_sha.h header when SHA library functions or
constants are required.  This replaces NEED_VB2_SHA_LIBRARY.

BUG=b:124141368, chromium:956474
TEST=make clean && make test-abuild
BRANCH=none

Change-Id: I9f32174dbf3de05fbe5279cb8017888757abf368
Signed-off-by: Joel Kitching <kitching@google.com>
Cq-Depend: chromium:1583820
Reviewed-on: https://review.coreboot.org/c/coreboot/+/32454
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>

util/cbfstool/cbfs_image.c

@@ -22,6 +22,7 @@
 #include <string.h>
 #include <strings.h>
 #include <commonlib/endian.h>
+#include <vb2_sha.h>
 
 #include "common.h"
 #include "cbfs_image.h"