xen/device-tree: Allow region overlapping with /memreserve/ ranges
There are some cases where the device tree exposes a memory range
in both /memreserve/ and reserved-memory node, in this case the
current code will stop Xen to boot since it will find that the
latter range is clashing with the already recorded /memreserve/
ranges.
Furthermore, u-boot lists boot modules ranges, such as ramdisk,
in the /memreserve/ part and even in this case this will prevent
Xen to boot since it will see that the module memory range that
it is going to add in 'add_boot_module' clashes with a /memreserve/
range.
When Xen populate the data structure that tracks the memory ranges,
it also adds a memory type described in 'enum membank_type', so
in order to fix this behavior, allow overlapping with the /memreserve/
ranges in the 'check_reserved_regions_overlap' function when a flag
is set.
In order to implement this solution, there is a distinction between
the 'struct membanks *' handled by meminfo_overlap_check(...) that
needs to be done, because the static shared memory banks doesn't have
a usable bank[].type field and so it can't be accessed, hence now
the 'struct membanks_hdr' have a 'enum region_type type' field in order
to be able to identify static shared memory banks in meminfo_overlap_check(...).
While there, set a type for the memory recorded using meminfo_add_bank()
from efi-boot.h.