powerpc/mm: Add physical address to Linux page table dump

The current page table dumper scans the Linux page tables and coalesces mappings
with adjacent virtual addresses and similar PTE flags. This behaviour is
somewhat broken when you consider the IOREMAP space where entirely unrelated
mappings will appear to be virtually contiguous. This patch modifies the range
coalescing so that only ranges that are both physically and virtually contiguous
are combined. This patch also adds to the dump output the physical address at
the start of each range.

Fixes: 8eb07b18

 ("powerpc/mm: Dump linux pagetables")
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
[mpe: Print the physicall address with 0x like the other addresses]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>