mmc: tmio: remove now unneeded seperate irq handlers

We removed installation of separate handlers previously, so we can also
remove the separate handlers.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>