binutils: NEWS: announce new RISC-V extensions

We picked up support for a few new extensions over the last weeks
(this may need further updating prior to the next release), list them
in the NEWS file.

binutils/ChangeLog:

	* binutils/NEWS: announce suuport for the new RISC-V
          extensions (Zicond, Zfa, XVentanaCondOps).

Signed-off-by: Philipp Tomsich <philipp.tomsich@vrull.eu>