ltq-vdsl-mei: avoid underscore in package name

As 07e1d88d7b ("kernel: avoid underscore in *6lowpan package names") shows,
underscores might cause build failures. Replace underscore with dash.

Signed-off-by: Sungbo Eo <mans0n@gorani.run>

package/kernel/lantiq/ltq-vdsl-mei/Makefile

@@ -38,7 +38,7 @@ define KernelPackage/ltq-vdsl-vr9-mei/description
 endef
 
 
-define Package/ltq-vdsl-mei_test
+define Package/ltq-vdsl-mei-test
   SECTION:=net
   CATEGORY:=Network
   TITLE:=Lantiq mei driver test tool
@@ -46,7 +46,7 @@ define Package/ltq-vdsl-mei_test
   DEPENDS:=@TARGET_lantiq_xrx200
 endef
 
-define Package/ltq-vdsl-mei_test/description
+define Package/ltq-vdsl-mei-test/description
 	Userland tool to directly control the mei driver, this is only needed
 	for test and development purposes.
 endef
@@ -80,9 +80,9 @@ endef
 
 $(eval $(call KernelPackage,ltq-vdsl-vr9-mei))
 
-define Package/ltq-vdsl-mei_test/install
+define Package/ltq-vdsl-mei-test/install
 	$(INSTALL_DIR) $(1)/bin
 	$(INSTALL_BIN) $(PKG_BUILD_DIR)/src/mei_cpe_drv_test $(1)/bin
 endef
 
-$(eval $(call BuildPackage,ltq-vdsl-mei_test))
+$(eval $(call BuildPackage,ltq-vdsl-mei-test))