ARM: sa11x0: assabet: ensure that GPIO27 is driven

GPIO27 is just connected to a CPLD input without any pull-ups or pull-
downs.  If GPIO27 is left as an input, it will float around mid-supply,
which for CMOS inputs is the worst place for a pin to be.  Ensure that
this pin is driven.

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