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>

board/htkw/mcx/mcx.c

@@ -130,6 +130,7 @@ static struct panel_config lcd_cfg = {
 	.load_mode      = 0x02, /* Frame Mode */
 	.panel_color	= 0,
 	.lcd_size	= PANEL_LCD_SIZE(800, 480),
+	.gfx_format	= GFXFORMAT_RGB24_UNPACKED,
 };
 
 int board_video_init(void)