gpio: add Penwell gpio support

Intel Penwell chip has two 96 pins GPIO blocks, which are very similiar as
Intel Langwell chip GPIO block, except for pin number difference. This
patch expends the original Langwell GPIO driver to support Penwell's.

Signed-off-by: Alek Du <alek.du@intel.com>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>