omap3: allow dynamic selection of gfx_format

Currently, omap3_dss_panel_config() sets gfx_format to a value that is hardcoded
in the code. This forces anyone who wants to use a different gfx_format to make
adjustments after calling omap3_dss_panel_config(). This could be avoided if the
value of gfx_format were parameterized as input for omap3_dss_panel_config().

Make gfx_format a field in struct panel_config, and update existing structs to
set this field to the value that was originally hard coded.

Cc: Wolfgang Denk <wd@denx.de>
Cc: Jeroen Hofstee <jeroen@myspectrum.nl>
Cc: Tom Rini <trini@ti.com>
Cc: Anatolij Gustschin <agust@denx.de>
Signed-off-by: Nikita Kiryanov <nikita@compulab.co.il>
Signed-off-by: Igor Grinberg <grinberg@compulab.co.il>
diff --git a/board/ti/beagle/beagle.h b/board/ti/beagle/beagle.h
index c0a94a9..6d71bbc 100644
--- a/board/ti/beagle/beagle.h
+++ b/board/ti/beagle/beagle.h
@@ -544,7 +544,8 @@
 	.panel_type	= 0x01, /* TFT */
 	.data_lines	= 0x03, /* 24 Bit RGB */
 	.load_mode	= 0x02, /* Frame Mode */
-	.panel_color	= DVI_BEAGLE_ORANGE_COL /* ORANGE */
+	.panel_color	= DVI_BEAGLE_ORANGE_COL, /* ORANGE */
+	.gfx_format	= GFXFORMAT_RGB24_UNPACKED,
 };
 
 static const struct panel_config dvid_cfg_xm = {
@@ -556,6 +557,7 @@
 	.panel_type	= 0x01, /* TFT */
 	.data_lines	= 0x03, /* 24 Bit RGB */
 	.load_mode	= 0x02, /* Frame Mode */
-	.panel_color	= DVI_BEAGLE_ORANGE_COL /* ORANGE */
+	.panel_color	= DVI_BEAGLE_ORANGE_COL, /* ORANGE */
+	.gfx_format	= GFXFORMAT_RGB24_UNPACKED,
 };
 #endif