ARCH:msm:clock Setting clock frequency to 40mhz

As the spi driver contains the max frequency in the device tree
as 40mhz we needed the same entry in order to increase the performance
of device

Change-Id: I859686fad8fac12011e9d29da7c9ddb745b7e7b4
Signed-off-by: Utkarsh Saxena <usaxena@codeaurora.org>