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/pm2fb.c b/drivers/video/pm2fb.c
index a52c61a..540249f 100644
--- a/drivers/video/pm2fb.c
+++ b/drivers/video/pm2fb.c
@@ -1837,6 +1837,8 @@
 
 module_param(mode_option, charp, 0);
 MODULE_PARM_DESC(mode_option, "Initial video mode e.g. '648x480-8@60'");
+module_param_named(mode, mode_option, charp, 0);
+MODULE_PARM_DESC(mode, "Initial video mode e.g. '648x480-8@60' (deprecated)");
 module_param(lowhsync, bool, 0);
 MODULE_PARM_DESC(lowhsync, "Force horizontal sync low regardless of mode");
 module_param(lowvsync, bool, 0);