wireless/wl12xx/wl1251: move TI WLAN modules to a common ti subdirectory

Move wl12xx and wl1251 modules into a new drivers/net/wireless/ti
directory.  Add a TI WLAN Kconfig option and Makefile to support this
change.

Signed-off-by: Luciano Coelho <coelho@ti.com>
Cc: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/Kconfig b/drivers/net/wireless/Kconfig
index abd3b71..5f58fa5 100644
--- a/drivers/net/wireless/Kconfig
+++ b/drivers/net/wireless/Kconfig
@@ -282,8 +282,7 @@
 source "drivers/net/wireless/p54/Kconfig"
 source "drivers/net/wireless/rt2x00/Kconfig"
 source "drivers/net/wireless/rtlwifi/Kconfig"
-source "drivers/net/wireless/wl1251/Kconfig"
-source "drivers/net/wireless/wl12xx/Kconfig"
+source "drivers/net/wireless/ti/Kconfig"
 source "drivers/net/wireless/zd1211rw/Kconfig"
 source "drivers/net/wireless/mwifiex/Kconfig"