linux-firmware: rtl8192cx: Add latest available firmware

Add latest available firmware binaries for RTL8192CX chipsets.
These new firmwares have been released in 2012, have been used
by the mainline kernel as preferred firmware since 3.13 and
even backported to stable branches.

(From OE-Core master rev: 2dc67b53)

Signed-off-by: Bhuvanchandra DV <bhuvanchandra.dv@toradex.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Joshua Lock <joshua.lock@collabora.co.uk>