iommu/arm-smmu-v3: Assign boolean values to a bool variable

Fix the following coccinelle warnings:

./drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c:36:12-26: WARNING: Assignment of 0/1 to bool variable

Signed-off-by: Kaixu Xia <kaixuxia@tencent.com>
Link: https://lore.kernel.org/r/1604744439-6846-1-git-send-email-kaixuxia@tencent.com


Signed-off-by: Will Deacon <will@kernel.org>