scsi: ufs-qcom: write the clock registers only if there is a change

If we write REG_UFS_SYS1CLK_1US & REG_UFS_TX_SYMBOL_CLK_NS_US registers
multiple times (especially when UFS symbol clocks are not running) then
it might make the HW to go back to default value of these registers.
This change updates above registers only if there is a change in these
registers value.

Change-Id: I7c94c477e52b36b26a1624fa3ddfa75a49916d58
Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>