s390: Avoid dynamic TLS relocs in PIE

No dynamic relocs are needed for TLS defined in an executable, the
TP relative offset is known at link time.

Fixes
FAIL: Build pr22263-1

bfd/
	PR ld/22263
	* elf64-s390.c (elf_s390_tls_transition): Use bfd_link_dll
	instead of bfd_link_pic for TLS.
	(elf_s390_check_relocs): Likewise.
	(allocate_dynrelocs): Likewise.
	(elf_s390_relocate_section): Likewise.