Implements R_PPC_ADDR32 handler for kldxref, addressing "kldxref: unhandled relocation type 1" when running "kldxref /boot/kernel" on powerpc 32 bits.
Apparently this relocation appeared after in-tree LLVM compiler upgrade between versions LLVM11 and 13.
In this change added a "where32" variable with type Elf32_Addr when destination is word32 on both 32 or 64 bits and guarded PPC64-only relocation with an ifdef. Comments are welcome.