omap2/3/4: Disable CONFIG_FB_OMAP in omap3_defconfig

Looks like CONFIG_FB_OMAP prevents somehow mounting root on MMC
at least on zoom3 for multi-omap. Disable CONFIG_FB until the
omap FB code is fixed.

This allows booting omap3_defconfig on various omaps. Tested on
2420-n8x0, 3430-n900, 3630-zoom3 and 4430-blaze. Note that n8x0
still has issues with starting user space because of TLS and
VFP.
Signed-off-by: Tony Lindgren <tony@atomide.com>

arch/arm/configs/omap3_defconfig

@@ -1359,16 +1359,8 @@ CONFIG_FB_TILEBLITTING=y
 # CONFIG_FB_METRONOME is not set
 # CONFIG_FB_MB862XX is not set
 # CONFIG_FB_BROADSHEET is not set
-CONFIG_FB_OMAP=y
+# CONFIG_FB_OMAP is not set
 CONFIG_FB_OMAP_LCD_VGA=y
-# CONFIG_FB_OMAP_031M3R is not set
-# CONFIG_FB_OMAP_048M3R is not set
-CONFIG_FB_OMAP_079M3R=y
-# CONFIG_FB_OMAP_092M9R is not set
-# CONFIG_FB_OMAP_LCDC_EXTERNAL is not set
-# CONFIG_FB_OMAP_LCD_MIPID is not set
-# CONFIG_FB_OMAP_BOOTLOADER_INIT is not set
-CONFIG_FB_OMAP_CONSISTENT_DMA_SIZE=2
 # CONFIG_OMAP2_DSS is not set
 CONFIG_BACKLIGHT_LCD_SUPPORT=y
 CONFIG_LCD_CLASS_DEVICE=y