Add PDC stable storage driver.  Also reorganise PA-RISC Kconfig a little.
Signed-off-by: Thibaut VARENE <varenet@parisc-linux.org>
Signed-off-by: Matthew Wilcox <willy@parisc-linux.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>