drm: Add 800x600 (SVGA) screen resolution to the built-in EDIDs

The 800x600 (SVGA) screen resolution was lacking in the set of
built-in selectable EDID screen resolutions that can be used to
repair misbehaving monitor firmware.

This patch adds the related data set and expands the documentation.
Note that the SVGA bit occupies a different byte to all the existing
users of the established timing bits forcing a rework of the
ESTABLISHED_TIMINGS_BITS macro.

Tested new EDID on an aged (and misbehaving) industrial LCD panel;
existing EDIDs still pass edid-decode's checksum checks.

Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: David Airlie <airlied@linux.ie>
Cc: Carsten Emde <C.Emde@osadl.org>
Cc: linux-doc@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/Documentation/EDID/HOWTO.txt b/Documentation/EDID/HOWTO.txt
index 7146db1..835db33 100644
--- a/Documentation/EDID/HOWTO.txt
+++ b/Documentation/EDID/HOWTO.txt
@@ -18,7 +18,7 @@
 individually prepared or corrected EDID data set in the /lib/firmware
 directory from where it is loaded via the firmware interface. The code
 (see drivers/gpu/drm/drm_edid_load.c) contains built-in data sets for
-commonly used screen resolutions (1024x768, 1280x1024, 1600x1200,
+commonly used screen resolutions (800x600, 1024x768, 1280x1024, 1600x1200,
 1680x1050, 1920x1080) as binary blobs, but the kernel source tree does
 not contain code to create these data. In order to elucidate the origin
 of the built-in binary EDID blobs and to facilitate the creation of