iommu: apple: Manage IOVA separately from global LMB mem map

iommu: apple: Manage IOVA separately from global LMB mem map

There is no overlap between the IOVA space managed by the iommu (here
the 32-bit address space) and physical RAM on Apple silicon systems. The
RAM starts at 0x10_0000_0000 or 0x100_0000_0000 so it's not possible to
manage the IOVA with the global memory LMB and use 1:1 translation.
In addition each device has its own iommu and does not need to share the
address space with all other devices. This should not be problem for
u-boot's limited use and hardware support.
Restore the private per instance LMB IOVA map.

Fixes: ed17a33fed2 ("lmb: make LMB memory map persistent and global")
Signed-off-by: Janne Grunau <j@jannau.net>