mmc: tmio: Switch to clock framework

mmc: tmio: Switch to clock framework

Switch the driver to using clk_get_rate()/clk_set_rate() instead of
caching the mclk frequency in it's private data. This is required on
the SDHI variant of the controller, where the upstream mclk need to
be adjusted when using UHS modes.

Platforms which do not support clock framework or do not support it
in eg. SPL default to 100 MHz clock.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
---
V2: - Fix build on certain platforms using SPL without clock framework
V3: - Turn clk_get_rate into a callback and fill it as needed on both
      renesas and socionext platforms