func_callerid: Document that CALLERID(pres) is available.

func_callerid: Document that CALLERID(pres) is available.

CALLERPRES() says that it's deprecated in favor of CALLERID(num-pres)
and CALLERID(name-pres).  But for channel driver that don't make a
distinction between the two (e.g. SIP), it makes more sense to get/set
both at once.  This change reveals the availability of CALLERID(pres),
CONNECTEDLINE(pres), REDIRECTING(orig-pres), REDIRECTING(to-pres) and
REDIRECTING(from-pres).

ASTERISK-25373 #close

Change-Id: I5614ae4ab7d3bbe9c791c1adf147e10de8698d7a