prov/psm3: remove uses of "psm2"

[BrendanCunningham]

Is your feature request related to a problem? Please describe.
In the latest libfabric/main source code (cmt dabd772, 26 May 2022), prov/psm3 uses “psm2” (case-insensitive) in the following ways:

• Header names, e.g. “psm2.h”, “psm2_am.h”.
• Type names, e.g. “psm2_error_t”, “psm2_ep_t”.
• Defines, e.g. “PSM2_OK”, “PSM2_INTERNAL_ERR”.
• At least two function names, both static and non-static, e.g. extern psm2_get_gpu_bars(), static psm2_check_phys_addr().

This creates false hits when searching from “PSM2” (i.e. not under prov/psm2) in the libfabric code base and presents multiple-definition and false-linking risks, a la #7757.

Describe the solution you'd like
Files under prov/psm3 renamed from "psm2*" to "psm3*". Occurrences of "psm2" (case-insensitive) in definition names replaced with psm3 or any other non-conflicting identifier. Particularly for any definitions that have global linkage or may end included in compilation units that do not directly include any psm3 headers.

Describe alternatives you've considered
None.

Additional context
Did not check for or consider occurrences of "psm2" in comments.