mmc: tmio: remove workaround for NON_REMOVABLE

PM has been reworked, so eMMC gets now detected on R-Car H3 ES1.0 and
2.0 as well as M3-N without the workaround. Card detect and write
protect also still work. Remove the workaround.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>