modpost: detect section mismatch for R_ARM_REL32

For ARM, modpost fails to detect some types of section mismatches.

  [test code]

    .section .init.data,"aw"
    bar:
            .long 0

    .section .data,"aw"
    .globl foo
    foo:
            .long bar - .

It is apparently a bad reference, but modpost does not report anything.

The test code above produces the following relocations.

  Relocation section '.rel.data' at offset 0xe8 contains 1 entry:
   Offset     Info    Type            Sym.Value  Sym. Name
  00000000  00000403 R_ARM_REL32       00000000   .init.data

Currently, R_ARM_REL32 is just skipped.

Handle it like R_ARM_ABS32.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>