mm: emit tracepoint when rss watermark is hit

mm: emit tracepoint when rss watermark is hit

Useful to track how rss is chanGing per tgid. Required for the
memory visibility work being done for Android.

OriGinal patch by Tim Murray:
https://partner-android-review.googlesource.com/c/kernel/private/msm-google/+/1081280

Changes from oriGinal patch:
- don't bloat mm_struct
- add some noise reduction to rss tracking

Mot-CRs-fixed: (CR)

Change-Id: Ief904334235ff4380244e5803d7853579e70d202
Signed-off-by: Joel Fernandes <joelaf@google.com>
Reviewed-on: https://gerrit.mot.com/1453726
SME-Granted: SME Approvals Granted
Tested-by: Jira Key
SLTApproved: Slta Waiver
Reviewed-by: Xiangpo Zhao <zhaoxp3@motorola.com>
Submit-Approved: Jira Key