ARM: shmobile: koelsch legacy: Add QSPI support

Enable support for the Spansion s25fl512s SPI FLASH on the Koelsch board:
  - Add QSPI platform device, resources, platform data, and pinmux,
  - Add FLASH data and MTD partitions.

Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>