ar71xx: add support for qca956x soc

This patch adds soc support for QCA9561 and TP9343.
TP9343 is a reduced version of QCA9561, which can be found in TP-LINK routers in China.
The qca956x_wmac has not yet been supported by ath9k.

tested on TL-WDR6500 and TL-WR882N v1 (Chinese version)

Signed-off-by: Weijie Gao <hackpascal@gmail.com>

SVN-Revision: 43744