drivers/video: fsl-diu-fb: add support for set_gamma ioctls

The MPC5121 BSP comes with a gamma_set utility that initializes the gamma
table via an ioctl.  Unfortunately, the ioctl number that utility uses
is defined improperly, but we can still support it.

Signed-off-by: Timur Tabi <timur@freescale.com>
diff --git a/include/linux/fsl-diu-fb.h b/include/linux/fsl-diu-fb.h
index 11c16a1..a1e8277 100644
--- a/include/linux/fsl-diu-fb.h
+++ b/include/linux/fsl-diu-fb.h
@@ -47,6 +47,15 @@
 #define MFB_GET_PIXFMT		_IOR('M', 8, __u32)
 
 /*
+ * The MPC5121 BSP comes with a gamma_set utility that initializes the
+ * gamma table.  Unfortunately, it uses bad values for the IOCTL commands,
+ * but there's nothing we can do about it now.  These ioctls are only
+ * supported on the MPC5121.
+ */
+#define MFB_SET_GAMMA		_IOW('M', 1, __u8)
+#define MFB_GET_GAMMA		_IOR('M', 1, __u8)
+
+/*
  * The original definitions of MFB_SET_PIXFMT and MFB_GET_PIXFMT used the
  * wrong value for 'size' field of the ioctl.  The current macros above use the
  * right size, but we still need to provide backwards compatibility, at least