Revert "arm: dma-mapping: WARN_ON if iova is not 128M aligned"

This reverts commit eb5c4e0e ("arm: dma-mapping: WARN_ON if iova
is not 128M aligned")
This warning is unnecessary and is forcing the clients to use the 128M
aligned virtual address. This warning is introduced thinking that the
clients may unnecessarily lose the unaligned part in the VA higher
end.But that's okay as this is just a VA and at the maximum user can
lost the 128M - 1 bytes of VA. And the minimum VA is represented as
always 128M. All these calculations are around the 4K page size.

Change-Id: Icfab10786cedf12ca860f20544b8ca973da4f40d
Signed-off-by: Charan Teja Reddy <charante@codeaurora.org>