x86-64: Treat R_X86_64_PLT32 as R_X86_64_PC32

Starting from binutils commit bd7ab16b4537788ad53521c45469a1bdae84ad4a:

https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=bd7ab16b4537788ad53521c45469a1bdae84ad4a

x86-64 assembler generates R_X86_64_PLT32, instead of R_X86_64_PC32, for
32-bit PC-relative branches.  Grub2 should treat R_X86_64_PLT32 as
R_X86_64_PC32.

Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
(cherry picked from commit 842c390469)

util/grub-module-verifier.c

@@ -19,6 +19,7 @@ struct grub_module_verifier_arch archs[] = {
       -1
     }, (int[]){
       R_X86_64_PC32,
+      R_X86_64_PLT32,
       -1
     }
   },