ppp: adjust with glibc and libcrypt-compat

glibc 2.39 has removed libcrypt completely.
solution: link against libxcrypt built with glibc compatibility.

Signed-off-by: Konstantin Demin <[email protected]>
Link: https://github.com/openwrt/openwrt/pull/19293
Signed-off-by: Hauke Mehrtens <[email protected]>

package/network/services/ppp/Makefile

@@ -55,14 +55,14 @@ endef
 
 define Package/ppp
 $(call Package/ppp/Default)
-  DEPENDS:=+kmod-ppp
+  DEPENDS:= +USE_GLIBC:libcrypt-compat +kmod-ppp
   TITLE:=PPP daemon
   VARIANT:=default
 endef
 
 define Package/ppp-multilink
 $(call Package/ppp/Default)
-  DEPENDS:=+kmod-ppp
+  DEPENDS:= +USE_GLIBC:libcrypt-compat +kmod-ppp
   TITLE:=PPP daemon (with multilink support)
   VARIANT:=multilink
 endef