fbdev: add removed option "mode" to keep compatibility

Add removed option "mode" to keep compatibility with existing setups.  The
option is back for pm2fb, tridentfb and vt8623fb drivers.

Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/video/vt8623fb.c b/drivers/video/vt8623fb.c
index 66305b6..f6895ef 100644
--- a/drivers/video/vt8623fb.c
+++ b/drivers/video/vt8623fb.c
@@ -112,6 +112,8 @@
 
 module_param(mode_option, charp, 0644);
 MODULE_PARM_DESC(mode_option, "Default video mode ('640x480-8@60', etc)");
+module_param_named(mode, mode_option, charp, 0);
+MODULE_PARM_DESC(mode, "Default video mode e.g. '648x480-8@60' (deprecated)");
 
 #ifdef CONFIG_MTRR
 module_param(mtrr, int, 0444);