staging: sm750: Fix lynxfb_ops_imageblit() if image->depth != 1

If image->depth != 1, lynxfb_ops_imageblit() should fallback to call
cfb_imageblit(), not return directly. Otherwise it can't display the
boot logo.

Cc: Teddy Wang <teddy.wang@siliconmotion.com>
Acked-by: NSudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: NHuacai Chen <chenhc@lemote.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/sm750fb/TODO

@@ -2,6 +2,7 @@ TODO:
 - lots of checkpatch cleanup
 - use kernel coding style
 - refine the code and remove unused code
+- Implement hardware acceleration for imageblit if image->depth > 1
 - check on hardware effects of removal of USE_HW_I2C and USE_DVICHIP (these two
 	are supposed to be sample code which is given here if someone wants to
 	use those functionalities)

drivers/staging/sm750fb/sm750.c

@@ -274,7 +274,10 @@ static void lynxfb_ops_imageblit(struct fb_info *info,
 		}
 		goto _do_work;
 	}
+	/* TODO: Implement hardware acceleration for image->depth > 1 */
+	cfb_imageblit(info, image);
 	return;
+
 _do_work:
 	/*
 	 * If not use spin_lock, system will die if user load driver