treewide: use name in define and eval lines

For consistency, use full name instead of $(PKG_NAME) in define and eval
lines for all packages.

I've seen reviews that asked to do this before, and I am asking the same
during reviews now. To avoid this in the future, fix this treewide so
when people use existing packages as example, we will not have to
request this change anymore.

This makes all packages consistent with both LEDE and OpenWrt base
repositories.

Signed-off-by: Stijn Tintel <stijn@linux-ipv6.be>

net/travelmate/Makefile

@@ -13,20 +13,20 @@ PKG_MAINTAINER:=Dirk Brenken <dev@brenken.org>
 
 include $(INCLUDE_DIR)/package.mk
 
-define Package/$(PKG_NAME)
+define Package/travelmate
 	SECTION:=net
 	CATEGORY:=Network
 	TITLE:=A wlan connection manager for travel router
 	PKGARCH:=all
 endef
 
-define Package/$(PKG_NAME)/description
+define Package/travelmate/description
 A wlan connection manager for travel router.
 Please see https://github.com/openwrt/packages/blob/master/net/travelmate/files/README.md for further information.
 
 endef
 
-define Package/$(PKG_NAME)/conffiles
+define Package/travelmate/conffiles
 /etc/config/travelmate
 endef
 
@@ -39,7 +39,7 @@ endef
 define Build/Compile
 endef
 
-define Package/$(PKG_NAME)/install
+define Package/travelmate/install
 	$(INSTALL_DIR) $(1)/usr/bin
 	$(INSTALL_BIN) ./files/travelmate.sh $(1)/usr/bin/
 
@@ -50,4 +50,4 @@ define Package/$(PKG_NAME)/install
 	$(INSTALL_CONF) ./files/travelmate.conf $(1)/etc/config/travelmate
 endef
 
-$(eval $(call BuildPackage,$(PKG_NAME)))
+$(eval $(call BuildPackage,travelmate))