tile: Check UNDEFWEAK_NO_DYNAMIC_RELOC

Don't generate dynamic relocation against weak undefined symbol if it
is resolved to zero.  FIXME: UNDEFWEAK_NO_DYNAMIC_RELOC may need to be
checked in more places.

	PR ld/22269
	* elf32-tilepro.c (allocate_dynrelocs): Discard dynamic
	relocations if UNDEFWEAK_NO_DYNAMIC_RELOC is true.
	(tilepro_elf_relocate_section): Don't generate dynamic
	relocation if UNDEFWEAK_NO_DYNAMIC_RELOC is true.
	* elfxx-tilegx.c (allocate_dynrelocs): Discard dynamic
	relocations if UNDEFWEAK_NO_DYNAMIC_RELOC is true.
	(tilegx_elf_relocate_section): Don't generate dynamic
	relocation if UNDEFWEAK_NO_DYNAMIC_RELOC is true.