ARM: dts: msm: Make allocation for diag as guaranteed on sdm630

Currently, memshare allocates 5MB memory to diag client on
receiving requests from modem. With the patch diag client
will be considered guaranteed on sdm630 to avoid memory
allocation failure on modem SSRs. Also being guaranteed
client allocated memory will never be freed.

CRs-Fixed: 2054448
Change-Id: I7b0780d064a27e8ebca9d31747ce1f9c18d84fdb
Signed-off-by: Mohit Aggarwal <maggarwa@codeaurora.org>