pcmcia: CompactFlash driver for PA Semi Electra boards

Driver for the CompactFlash slot on the PA Semi Electra eval board. It's
a simple device sitting on localbus, with interrupts and detect/voltage
control over GPIO.

The driver is implemented as an of_platform driver, and adds localbus
as a bus being probed by the of_platform framework.

[akpm@linux-foundation.org: cleanups]
[olof@lixom.net: fix build]
Signed-off-by: Olof Johansson <olof@lixom.net>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Milton Miller <miltonm@bga.com>
Cc: Kumar Gala <galak@gate.crashing.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>