[ARM] 4480/1: pxa: change the pxa device naming scheme

1. for common devices across all the pxa variants, the names
   are changed to be:
     "pxa_device_xxx"

2. for pxa25x or pxa27x specific devices, the names are
   changed to be:
     "pxa25x_device_xxx", or
     "pxa27x_device_xxx"

Signed-off-by: eric miao <eric.y.miao@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>