mmc: tmio: remove workaround for NON_REMOVABLE

RPM handling has been improved twice since this comment, and also SCC
handling has been improved a lot. All the testing we did (Geert's and
Niklas' and Wolfram's board farms) with the workaround removed did not
lead to problems, so it is time to get rid of it to the best of our
knowledge.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Link: https://lore.kernel.org/r/20210218110224.6910-1-wsa+renesas@sang-engineering.com


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