compat: Remove is_power_of_2() definition

Use the is_power_of_2() definition from log2.h to align with the
kernel implementation.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Heiko Schocher <hs@denx.de>
Reviewed-by: Jagan Teki <jteki@openedev.com>
diff --git a/drivers/mtd/ubi/build.c b/drivers/mtd/ubi/build.c
index f0a3b67..f484e62 100644
--- a/drivers/mtd/ubi/build.c
+++ b/drivers/mtd/ubi/build.c
@@ -30,7 +30,7 @@
 #include <linux/slab.h>
 #include <linux/major.h>
 #else
-#include <linux/compat.h>
+#include <linux/log2.h>
 #endif
 #include <linux/err.h>
 #include <ubi_uboot.h>