mmc: pxamci: Delete platform data handling of CD and WP

This deletes the code dealing with handling card detect
and write protect passed in as platform data and makes
the host rely on just GPIO descriptors.

The card read only inversion flag has to be kept around
for now, as the core cannot handle the inversion flags
on the descriptors yet.

Since we can now rely on the descriptors to have the
right polarity, we set the "override_active_level" to
false in mmc_gpiod_request_cd() and mmc_gpiod_request_ro().

Cc: Daniel Mack <daniel@zonque.org>
Cc: Robert Jarzmik <robert.jarzmik@free.fr>
Cc: Bartosz Golaszewski <brgl@bgdev.pl>
Cc: Andrea Adami <andrea.adami@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>