[PATCH v1] linux-gen: timer: use new 128-bit atomic APIs for timer processing functions

[Malvika-Gupta]

Use newer and ODP standardized 128-bit atomic APIs in the timer processing functions. ODP timer library was the sole user of the _odp_atomic_u128_cmp_xchg_mm() API so this can be removed as well.

The first commit is a part of PR #1610 which has been approved. It will be dropped when the PR is merged