mmc: core: Resume clk scaling after hw reset

Fix clock scaling in hw reset path to resume clock scaling
after hw reset.

Also hw reset during mmc card initialization is not required.
This may unnecessarily add latency in mmc card initialization
upon addition of hw reset recovery support.

Change-Id: I0c3580b6b113d4d1afad5a9e24fe9fec4deea5bc
Signed-off-by: Ram Prakash Gupta <rampraka@codeaurora.org>