devel/elfutils: fix build with lld 17

Building devel/elfutils with lld 17 results in the following link error:

  cc -std=gnu99 -Wall -Wshadow -Wformat=2 -Wold-style-definition -Wstrict-prototypes    -Wnull-dereference -Wimplicit-fallthrough -Werror -Wunused -Wextra     -D_FORTIFY_SOURCE=3 -O2 -pipe  -I/usr/local/include -I/usr/local/share/gnulib/lib -Wno-error -Wno-format-nonliteral -Wno-null-dereference -Wno-unused-value -DFREEBSD_HAS_MEMPCPY -fstack-protector-strong -fno-strict-aliasing   /usr/local/lib/libargp.so  /usr/local/lib/libintl.so -fstack-protector-strong  -Wl,--build-id -o libelf.so -shared -Wl,-z,defs -Wl,-z,relro -o libelf.so \
          -Wl,--soname,libelf.so.1 \
          -Wl,--version-script,libelf.map,--no-undefined \
          -Wl,--whole-archive libelf_pic.a -Wl,--no-whole-archive \
          ../lib/libeu.a -lz
  ld: error: version script assignment of 'ELFUTILS_1.0' to symbol 'elf_scncnt' failed: symbol not defined
  cc: error: linker command failed with exit code 1 (use -v to see invocation)

Upstream removed the symbol which apparently was never implemented in:
<https://sourceware.org/git/?p=elfutils.git;a=commit;h=09e61a65953ed814d9e970f7f9ffb9c2d8cda477>.

I tried adding this via PATCH_SITES and PATCHFILES, but it looks like
the ports framework chokes on URLs with ? in them, so I'm adding a
regular patch file in devel/elfutils/files/patch-libelf_libelf.map file
instead.

PR:		273998
Approved by:	maintainer timeout (2 weeks)
MFH:		2023Q4

devel/elfutils/files/patch-libelf_libelf.map

@@ -0,0 +1,10 @@
+--- libelf/libelf.map.orig	2022-04-25 20:56:39 UTC
++++ libelf/libelf.map
+@@ -50,7 +50,6 @@ ELFUTILS_1.0 {
+     elf_rand;
+     elf_rawdata;
+     elf_rawfile;
+-    elf_scncnt;
+     elf_strptr;
+     elf_update;
+     elf_version;