valkyriefb: various fixes

Valkyriefb and macfb will adopt the same card if they get the chance, so
remove valkyrie support from macfb. Also fix the "valkyriefb: can't do
832x624x8" problem reported by Raylynn Knight some time ago, by adding
vmode 13 support for CONFIG_MAC. Also add vmode 11 since that works too.
Make use of the monitor sense lines on 68k Macs too. Also some cleanups.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
diff --git a/drivers/video/valkyriefb.c b/drivers/video/valkyriefb.c
index 4bb9a0b..6b52bf6 100644
--- a/drivers/video/valkyriefb.c
+++ b/drivers/video/valkyriefb.c
@@ -69,7 +69,7 @@
 #ifdef CONFIG_MAC
 /* We don't yet have functions to read the PRAM... perhaps we can
    adapt them from the PPC code? */
-static int default_vmode = VMODE_640_480_67;
+static int default_vmode = VMODE_CHOOSE;
 static int default_cmode = CMODE_8;
 #else
 static int default_vmode = VMODE_NVRAM;
@@ -326,11 +326,11 @@
 
 #ifdef CONFIG_MAC
 	if (!MACH_IS_MAC)
-		return 0;
+		return -ENODEV;
 	if (!(mac_bi_data.id == MAC_MODEL_Q630
 	      /* I'm not sure about this one */
 	    || mac_bi_data.id == MAC_MODEL_P588))
-		return 0;
+		return -ENODEV;
 
 	/* Hardcoded addresses... welcome to 68k Macintosh country :-) */
 	frame_buffer_phys = 0xf9000000;