graphics/mesa-dri: fix build with lld 17

Some symbols in mesa's linker version scripts are not always defined,
depending on configuration options. Suppress errors with lld >= 17 due
to these undefined symbols.

This applies to multiple mesa ports, such as mesa-dri, mesa-libs,
mesa-gallium-*, etc. So add the LDFLAGS setting to Makefile.common.

PR:		273981
Approved by:	x11 (manu)
MFH:		2023Q3

graphics/mesa-dri/Makefile.common

@@ -88,3 +88,8 @@ CONFIGURE_ENV+=	LLVM_CONFIG=llvm-config${LLVM_DEFAULT}
 
 LDFLAGS+=	-Wl,-rpath=${LOCALBASE}/llvm${LLVM_DEFAULT}/lib
 MESON_ARGS+=	-Dllvm=enabled
+
+# Some symbols in mesa's linker version scripts are not always defined,
+# depending on configuration options. Suppress errors with lld >= 17 due to
+# these undefined symbols.
+LDFLAGS+=	-Wl,--undefined-version