Use pselect in OS_DoSelect to avoid needed conversions

[skliper]

Is your feature request related to a problem? Please describe.
Could avoid timespec to timeval conversion:

osal/src/os/portable/os-impl-bsd-select.c

Lines 204 to 206 in ead5723

	/* note that the tv_sec and tv_usec/tv_nsec values are all signed longs, so OK to subtract */
	tv.tv_sec = ts_end.tv_sec - ts_now.tv_sec;
	tv.tv_usec = (ts_end.tv_nsec - ts_now.tv_nsec) / 1000;

if pselect was used here:

osal/src/os/portable/os-impl-bsd-select.c

Line 221 in ead5723

os_status = select(maxfd + 1, rd_set, wr_set, NULL, tvptr);

Describe the solution you'd like
Use pselect, need to check VxWorks/RTEMS support

Describe alternatives you've considered
Leave as-is (future work)

Additional context
None

Requester Info
Jacob Hageman - NASA/GSFC, OSAL code review