Revert "arm: dma: Allow CMA pages to not have a kernel mapping"

This reverts commit 0b06cd5c.

The meaning of DMA_ATTR_NO_KERNEL_MAPPING changes, it will not remove
kernel mapping, just return the page pointer directly, so make 32 bit
align with 64 bit.

Change-Id: I905f2faa11681dff745191928345fef00c9ec796
Signed-off-by: Qingqing Zhou <qqzhou@codeaurora.org>