MAINTAINERS: Update QUALCOMM IOMMU after Arm SMMU drivers move

MAINTAINERS: Update QUALCOMM IOMMU after Arm SMMU drivers move

Commit 8c30d0a3ab45 ("iommu/arm-smmu: Move Arm SMMU drivers into their own
subdirectory") moved drivers/iommu/qcom_iommu.c to
drivers/iommu/arm/arm-smmu/qcom_iommu.c amongst other moves, adjusted some
sections in MAINTAINERS, but missed adjusting the QUALCOMM IOMMU section.

Hence, ./scripts/get_maintainer.pl --self-test=patterns complains:

  warning: no file matches    F:    drivers/iommu/qcom_iommu.c

Update the file entry in MAINTAINERS to the new location.

Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20200825053828.4166-1-lukas.bulwahn@gmail.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>