ar71xx: remove 'Target/Description' from main Makefile

Ensure that menuconfig shows the correct help text for
subtargets.

Based on the patch by Stefan Agner:
http://patchwork.openwrt.org/patch/4123/

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>

SVN-Revision: 38507

target/linux/ar71xx/Makefile

@@ -22,8 +22,4 @@ DEFAULT_PACKAGES += \
 	kmod-ledtrig-default-on kmod-ledtrig-timer kmod-ledtrig-netdev \
 	kmod-ath9k wpad-mini uboot-envtools
 
-define Target/Description
-	Build firmware images for Atheros AR7xxx/AR9xxx based boards.
-endef
-
 $(eval $(call BuildTarget))