[ARM] 2883/1: PXA Sharpsl: Add detection of new PXA based Zaurii machine types

Patch from Richard Purdie

Add machine detection routines for several new models of PXA based Zaurii
(SL-C3000 - Spitz, SL-C1000 - Akita, SL-C3100 - Borzoi, SL-C6000 - Tosa).
Sharp continue to use broken bootloaders in ROM.

Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>