arm64: Make DMA coherent and strongly ordered mappings not executable

arm64: Make DMA coherent and strongly ordered mappings not executable

commit de2db7432917a82b62d55bb59635586eeca6d1bd upstream.

pgprot_{dmacoherent,writecombine,noncached} don't need to generate
executable mappings with side-effects like __sync_icache_dcache() being
called when the mapping is in user space.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Reported-by: Bharat Bhushan <Bharat.Bhushan@freescale.com>
Tested-by: Laura Abbott <lauraa@codeaurora.org>
Tested-by: Bharat Bhushan <Bharat.Bhushan@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 73e8697b71fa956642403304b96442fd4b57ce97)
Signed-off-by: Mark Brown <broonie@linaro.org>