update common base header files

IS_ENABLED is defined in kconfig.h, thus, should be included in
libpayload.h.

BUG=none
BRANCH=tot
TEST=built coreboot/libpayload for veyron_jerry

Change-Id: I9c5879b6125ac66a75a507ab07a6816ab54ed0ba
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: 51dcd58a841009081fdefcadf9aa74286152dde6
Original-Change-Id: I30e6d87c9de827a214a6100449cd716e773c2ba3
Original-Signed-off-by: Daisuke Nojiri <dnojiri@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/282587
Original-Reviewed-by: Randall Spangler <rspangler@chromium.org>
Reviewed-on: http://review.coreboot.org/10781
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
diff --git a/payloads/libpayload/include/stddef.h b/payloads/libpayload/include/stddef.h
index bb2971d..fe455b8 100644
--- a/payloads/libpayload/include/stddef.h
+++ b/payloads/libpayload/include/stddef.h
@@ -16,7 +16,15 @@
 #define offsetof(TYPE, MEMBER)	((size_t) &((TYPE *) 0)->MEMBER)
 #define member_size(TYPE, MEMBER)	(sizeof(((TYPE *) 0)->MEMBER))
 
+#define check_member(structure, member, offset) _Static_assert( \
+	offsetof(struct structure, member) == offset, \
+	"`struct " #structure "` offset for `" #member "` is not " #offset)
+
 /* Standard units. */
 #define KiB (1<<10)
 #define MiB (1<<20)
 #define GiB (1<<30)
+
+#define KHz (1000)
+#define MHz (1000*KHz)
+#define GHz (1000*MHz)