libcflat: add IS_ALIGNED() macro, and page sizes

These macros will be useful to do page alignment checks.
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
[drew: also added SZ_64K and changed to shifts]
Signed-off-by: Andrew Jones <drjones@redhat.com>

lib/libcflat.h

@@ -33,6 +33,12 @@
 #define __ALIGN_MASK(x, mask)	(((x) + (mask)) & ~(mask))
 #define __ALIGN(x, a)		__ALIGN_MASK(x, (typeof(x))(a) - 1)
 #define ALIGN(x, a)		__ALIGN((x), (a))
+#define IS_ALIGNED(x, a)	(((x) & ((typeof(x))(a) - 1)) == 0)
+
+#define SZ_4K			(1 << 12)
+#define SZ_64K			(1 << 16)
+#define SZ_2M			(1 << 21)
+#define SZ_1G			(1 << 30)
 
 typedef uint8_t		u8;
 typedef int8_t		s8;