mmc: sdhci-msm: Use actual clock for mclk_freq calculation

Due to SSC (Spread Spectrum) sdcc2 clock wont be 202Mhz but will be
slightly less than 202Mhz (201.99).
For yupik we are using floor ops in clock's driver to take the
floor value for the frequency passed from sdhc driver.
For 201.99Mhz clk_round_rate API will also round to the floor value leading
to 100Mhz for our mclk_freq calculation.

Instead of clk_round_rate and dividing by two logic we can directly
use actual clock which will be supplied to the card in mclk_freq
calculation.

Change-Id: I57a864b98d85573eb9038b6d6f502f83850eed73
Signed-off-by: Sarthak Garg <sartgarg@codeaurora.org>