ARM: dts: msm: Update memdump table names to support minidump on SDM845

Minidump allocs maximum of 12 characters for region name, use short
names to add memdump table regions to minidump table.

And add dload_type node to support storing minidump at rawdump
partition.

Change-Id: I7351d0fc0e5b564e517506a2fec3dddbc605aa7e
Signed-off-by: Lingutla Chandrasekhar <clingutla@codeaurora.org>