pxafb: add transparency field to pxafb_mode_info struct

This allows to select either RGB565 (transparency 0) or RGBT555
(transparency 1) from the mode info

Signed-off-by: Pieter Grimmerink <p.grimmerink@inepro.com>
Signed-off-by: Eric Miao <eric.y.miao@gmail.com>

arch/arm/mach-pxa/include/mach/pxafb.h

@@ -76,7 +76,8 @@ struct pxafb_mode_info {
 	u_char		bpp;
 	u_int		cmap_greyscale:1,
 			depth:8,
-			unused:23;
+			transparency:1,
+			unused:22;
 
 	/* Parallel Mode Timing */
 	u_char		hsync_len;

drivers/video/pxafb.c

@@ -398,6 +398,7 @@ static void pxafb_setmode(struct fb_var_screeninfo *var,
 	var->lower_margin	= mode->lower_margin;
 	var->sync		= mode->sync;
 	var->grayscale		= mode->cmap_greyscale;
+	var->transp.length	= mode->transparency;
 
 	/* set the initial RGBA bitfields */
 	pxafb_set_pixfmt(var, mode->depth);