ARM: 8039/1: pj4: enable iWMMXt only if CONFIG_IWMMXT is set

This fixes PJ4 coprocessor init to only expose iWMMXt capabilities,
if the corresponding kernel support for iWMMXt is enabled.

Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Tested-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Tested-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>