P31XX: add BOARD_NO_APSME_ATTR flag

nl80211:
The AP SME condition causes problems on driver initialization if the
NL80211_ATTR_DEVICE_AP_SME is not available.

Using this buildflag will fix wifi-tethering.

Change-Id: I697c6100834e251d2eca29e335751c412bb3b4f1