[ARM] 3094/1: remove PLD stuff from old uaccess code

Patch from Nicolas Pitre

ARM processors that have pld instructions are not using those copy_user
implementation anymore.  Let's remove the useless PLD lines which were
half wrong anyway.

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>