mmc: sh-mmcif: update to print version and bus clock rate on probe

Change the initial print to show chip version and the bus rate it is
working at instead of the driver version. This is more useful information
as we already know which driver version from the kernel it is in.

Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>