This patch adds iomapping for the region2 section of memory on the SBZ.
This memory region is used in later patches for setting inputs and
outputs. If the mapping fails, the quirk is changed back to QUIRK_NONE
to avoid attempts to write to uninitialized memory.

It also adds a new exit sequence to unmap the iomem for the SBZ.

[ Reordered linux/*.h inclusion in the patch by tiwai ]
Signed-off-by: Connor McAdams <conmanx360@gmail.com>
Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>