mmc: meson-gx: remove meson_mmc_get_cd

MMC core only checks whether return value of .get_cd() equals zero.
Therefore -ENOSYS and 1 are effectively the same and the function
can be removed.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Link: https://lore.kernel.org/r/16502040-3beb-a3cc-b28d-28184fba0f10@gmail.com


Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>