fbdev: Add fb_append_extra_logo()

Add fb_append_extra_logo(), to append extra lines of logos below the standard
Linux logo.

Signed-off-by: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Signed-off-by: Geoff Levand <geoffrey.levand@am.sony.com>
Acked-By: James Simmons <jsimmons@infradead.org>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/linux_logo.h b/include/linux/linux_logo.h
index 9c01bde..08a9296 100644
--- a/include/linux/linux_logo.h
+++ b/include/linux/linux_logo.h
@@ -33,5 +33,13 @@
 };
 
 extern const struct linux_logo *fb_find_logo(int depth);
+#ifdef CONFIG_FB_LOGO_EXTRA
+extern void fb_append_extra_logo(const struct linux_logo *logo,
+				 unsigned int n);
+#else
+static inline void fb_append_extra_logo(const struct linux_logo *logo,
+					unsigned int n)
+{}
+#endif
 
 #endif /* _LINUX_LINUX_LOGO_H */