ARM: 6852/1: EP93xx: Remove ep93xx_gpio_dbg_show function

The interrupt printing functionality in the ep93xx gpio debugfs function
does not behave as expected. It prints [interrupt] beside all pins which
are capable of being interrupts, not just those which are currently
configured as interrupts.

The best solution is just to remove the custom ep93xx gpio debugfs
function all together. The generic gpiolib one is good enough.

Signed-off-by: Ryan Mallon <ryan@bluewatersys.com>
Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>