Check for PPC32 in imsttfb

This is the correct fix according to Paul Mackerras and allows an
allyesconfig on PPC64 to build.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Paul Mackerras <paulus@samba.org>
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>

drivers/video/imsttfb.c

@@ -1391,7 +1391,7 @@ init_imstt(struct fb_info *info)
 		}
 	}
 
-#if USE_NV_MODES && defined(CONFIG_PPC)
+#if USE_NV_MODES && defined(CONFIG_PPC32)
 	{
 		int vmode = init_vmode, cmode = init_cmode;