ramips-mt7620: add new subtarget with some Gl.Inet devices

targets/ramips-mt7620

+packages '-wpad-mini' # clashes with hostapd-mini
+
+# GL Innovations
+device gl-mt300a gl-mt300a
+factory
+
+device gl-mt300n gl-mt300n
+factory
+
+device gl-mt750 gl-mt750
+factory

targets/targets.mk

@@ -13,6 +13,7 @@ $(eval $(call GluonTarget,ar71xx,mikrotik)) # BROKEN: no sysupgrade support
 $(eval $(call GluonTarget,brcm2708,bcm2710)) # BROKEN: Untested
 $(eval $(call GluonTarget,ipq806x)) # BROKEN: Untested
 $(eval $(call GluonTarget,mvebu)) # BROKEN: No AP+IBSS or 11s support
+$(eval $(call GluonTarget,ramips,mt7620)) # BROKEN: No AP+IBSS support
 $(eval $(call GluonTarget,ramips,mt7621)) # BROKEN: No AP+IBSS support, 11s has high packet loss
 $(eval $(call GluonTarget,ramips,mt7628)) # BROKEN: No AP+IBSS support
 $(eval $(call GluonTarget,ramips,rt305x)) # BROKEN: No AP+IBSS support