lcd: dt: extract simplefb support

We now have api functions that can support compiling simplefb code as its own
module. Since this code is not part of the display functionality, extract it
to its own file.

Raspberry Pi is updated to accommodate the changes.

Signed-off-by: Nikita Kiryanov <nikita@compulab.co.il>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Bo Shen <voice.shen@atmel.com>
Tested-by: Josh Wu <josh.wu@atmel.com>
Cc: Simon Glass <sjg@chromium.org>
Cc: Anatolij Gustschin <agust@denx.de>
Cc: Stephen Warren <swarren@wwwdotorg.org>

include/fdt_simplefb.h

@@ -0,0 +1,14 @@
+/*
+ * Simplefb device tree support
+ *
+ * (C) Copyright 2015
+ * Stephen Warren <swarren@wwwdotorg.org>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#ifndef _FDT_SIMPLEFB_H_
+#define _FDT_SIMPLEFB_H_
+int lcd_dt_simplefb_add_node(void *blob);
+int lcd_dt_simplefb_enable_existing_node(void *blob);
+#endif