iommu/ipmmu-vmsa: Drop LPAE Kconfig dependency

Neither the ARM page table code enabled by IOMMU_IO_PGTABLE_LPAE
nor the IPMMU_VMSA driver actually depends on ARM_LPAE, so get
rid of the dependency.

Tested with ipmmu-vmsa on r8a7794 ALT and a kernel config using:
 # CONFIG_ARM_LPAE is not set

Signed-off-by: Magnus Damm <damm+renesas@opensource.se>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Joerg Roedel <jroedel@suse.de>