MLK-17621-1 mmc: remove the feature of setting slot index via devicetree alias

MLK-17621-1 mmc: remove the feature of setting slot index via devicetree alias

This patch remove the commit 3d8a438c53f3 ("mmc: Allow setting slot index via
devicetree alias"),which wrongly use the function ida_simple_get(), causing
this function return unexpected result when the reserved alias index value is
not 0.

In the meantime, the 'devidx' in the mmc block layer code just impact the minor
device number, no need to align the minor device number and the slot index.

Here remove upper mentioned patch, and will reform the feature of setting slot
index via devicetree alias in the next few patches.

This patch also remove one other related patch:
commit 82f323ade111 ("MLK-12617 mmc: Fix compile error when CONFIG_MMC=m").

Reported-by: Leonard Crestez <leonard.crestez@nxp.com>
Acked-by: Dong Aisheng <aisheng.dong@nxp.com>
Signed-off-by: Haibo Chen <haibo.chen@nxp.com>