mmc: tmio: remove tmio_mmc_k(un)map_atomic helpers

mmc: tmio: remove tmio_mmc_k(un)map_atomic helpers

After a8402aed8ca5 ("mmc: tmio_mmc_core: Remove
local_irq_{save,restore}() around k[un]map_atomic()") and ac91578a6812
("mmc: tmio_mmc_core: Replace kmap_atomic() with kmap_local_page()"),
the helpers contain just a single call. Putting it directly in the code
makes it actually more readable. More so, because we now avoid the
'offset' calculation when mapping/unmapping and just use it when we need
it in the copy routines.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Link: https://lore.kernel.org/r/20221102125430.28466-2-wsa+renesas@sang-engineering.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>