softpll: single entry point to rule them all (GM, master, slave modes), fully non-blocking operation

Conflicts:

	rt/dev/softpll_ng.c

Conflicts:

	rt/dev/softpll_ng.c

Conflicts:

	rt/dev/softpll_ng.c

Conflicts:

	modules/wrsw_rtu/rtu_wishbone_slave.vhd

This argument is documented as optional!

cleanup, removed obsolete/unused functions from libposix, removed remaining references to UTC timescale

freestanding-wrapper: fix ptpd_netif_read_calibration_data(), check whether deltaTx and deltaRx pointers are not NULL to prevent memory corruption

freestanding-wrapper: fix ptpd_netif_read_calibration_data() to check whether clock_period pointer is not NULL, prevent from mamory corruption