spi_qsd: Correction in DMA mode check.

Due to bug in the if() condition msm_use_dm function
is always returning '0' when cs_change is true. Due to
this issue the DMA mode is not bieng used when it has to be.

This patch fixes this issue.

CRs-Fixed: 475841
Change-Id: Ib4d7c4f816c2df71683d0901eb0fab78f441a208
Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>