mmc: tmio: use SDIO master interrupt bit only when allowed

The master bit to enable SDIO interrupts can only be accessed if
SCLKDIVEN bit allows that. However, the core uses the SDIO enable
callback at times when SCLKDIVEN forbids the change. This leads to
"timeout waiting for SD bus idle" messages.

We now activate the master bit in probe once if SDIO is supported. IRQ
en-/disabling will be done now by the individual IRQ enablement bits
only.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Yasushi SHOJI <yashi@atmark-techno.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>