imxfb: calculate bpix value from bits_per_pixel

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
diff --git a/arch/arm/plat-mxc/include/mach/imxfb.h b/arch/arm/plat-mxc/include/mach/imxfb.h
index 9f01011..66259f6 100644
--- a/arch/arm/plat-mxc/include/mach/imxfb.h
+++ b/arch/arm/plat-mxc/include/mach/imxfb.h
@@ -13,7 +13,8 @@
 #define PCR_BPIX_4	(2 << 25)
 #define PCR_BPIX_8	(3 << 25)
 #define PCR_BPIX_12	(4 << 25)
-#define PCR_BPIX_16	(4 << 25)
+#define PCR_BPIX_16	(5 << 25)
+#define PCR_BPIX_18	(6 << 25)
 #define PCR_PIXPOL	(1 << 24)
 #define PCR_FLMPOL	(1 << 23)
 #define PCR_LPPOL	(1 << 22)