mmc: tmio: factor out TAP usage

TAPs are Renesas SDHI specific. Now that we moved all handling to the
SDHI core, we can also move the definitions from the TMIO struct to the
SDHI one.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Link: https://lore.kernel.org/r/20200129203709.30493-6-wsa+renesas@sang-engineering.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>