[ARM] 3179/1: Update/correct Zaurus Kconfig entries

Patch from Richard Purdie

Add iWMMX Extentions for the pxa27x based Zaurus models and
fix a couple of minor mistakes in the PXA Kconfig file.

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