ppp: build the PPPoA plugin without libatm

The PPPoA plugin only uses text2atm() and text2qos() from libatm. ppp
ships copies of both and uses them unless configured --with-atm, so
link the bundled copies and drop the dependency on linux-atm.

Assisted-by: Claude:claude-opus-5-5
Signed-off-by: Julius Bairaktaris <julius@bairaktaris.de>
Link: https://github.com/openwrt/openwrt/pull/25707
Signed-off-by: Robert Marko <robimarko@gmail.com>

package/network/services/ppp/Makefile

@@ -10,7 +10,7 @@ include $(INCLUDE_DIR)/kernel.mk
 
 PKG_NAME:=ppp
 PKG_VERSION:=2.5.4
-PKG_RELEASE:=1
+PKG_RELEASE:=2
 
 PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.gz
 PKG_SOURCE_URL:=https://download.samba.org/pub/ppp
@@ -37,8 +37,8 @@ CONFIGURE_ARGS += \
 	--enable-ipv6cp \
 	--enable-microsoft-extensions \
 	--enable-plugins \
-	--with-atm \
 	--with-static-pcap \
+	--without-atm \
 	--without-openssl \
 	--without-pam \
 	--without-pcap
@@ -79,7 +79,7 @@ endef
 
 define Package/ppp-mod-pppoa
 $(call Package/ppp/Default)
-  DEPENDS:=@(PACKAGE_ppp||PACKAGE_ppp-multilink) +linux-atm +kmod-pppoa
+  DEPENDS:=@(PACKAGE_ppp||PACKAGE_ppp-multilink) +kmod-pppoa
   TITLE:=PPPoA plugin
 endef