wil6210: Move dma mask setting after platform initialization

Platform specific initialization may initialize SMMU
(if available) which updates dma operations, therefore
setting of DMA mask needs to be done after platform
specific initialization.

Change-Id: I7b0e90e5e3d03816146f2f73a55dc858e03646dd
Signed-off-by: Hamad Kadmany <hkadmany@codeaurora.org>
[merez@codeaurora.org: fixed trivial conflicts]
Signed-off-by: Maya Erez <merez@codeaurora.org>