Add padding to the plt section so that its size is a multiple of its

Add padding to the plt section so that its size is a multiple of its
entry size.
	* elf32-tilepro.c (allocate_dynrelocs): Use PLT_ENTRY_SIZE as size
	of header.
	(tilepro_plt_entry_build): Account for new header size.
	(tilepro_elf_finish_dynamic_sections): Ditto.
	(tilepro_elf_plt_sym_val): Ditto.
	* elfxx-tilegx.c (allocate_dynrelocs): Use PLT_ENTRY_SIZE as size
	of header + tail.
	(tilegx_elf_finish_dynamic_sections): Account for new padding.