[PATCH] fbdev: simplefb: limit its use to DRM_SIMPLEDRM=n

When DRM_SIMPLEDRM=m, all of FB_CFB_{FILLRECT,COPYAREA,IMAGEBLIT} are =m,
causing undefined references in fbdev/simplefb.o.

By restricting FB_SIMPLEFB to be set only when DRM_SIMPLEDRM is not set,
the FB_CFB_* symbols are =y and the build completes without these
undefined references.

IOW, really "disable simplefb if simpledrm has been selected".

or1k-linux-ld: drivers/video/fbdev/simplefb.o:(.rodata+0x2c): undefined reference to `cfb_fillrect'
or1k-linux-ld: drivers/video/fbdev/simplefb.o:(.rodata+0x30): undefined reference to `cfb_copyarea'
or1k-linux-ld: drivers/video/fbdev/simplefb.o:(.rodata+0x34): undefined reference to `cfb_imageblit'

Fixes: 11e8f5fd223b ("drm: Add simpledrm driver")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: kernel test robot <redacted>
Cc: Hans de Goede <redacted>
Cc: linux-fbdev@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc: Thomas Zimmermann <tzimmermann@suse.de>
---
 drivers/video/fbdev/Kconfig |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- linux-next-20210716.orig/drivers/video/fbdev/Kconfig
+++ linux-next-20210716/drivers/video/fbdev/Kconfig

@@ -2192,7 +2192,7 @@ config FB_HYPERV
 
 config FB_SIMPLE
 	bool "Simple framebuffer support"
-	depends on (FB = y) && !DRM_SIMPLEDRM
+	depends on (FB = y) && DRM_SIMPLEDRM=n
 	select FB_CFB_FILLRECT
 	select FB_CFB_COPYAREA
 	select FB_CFB_IMAGEBLIT