IBM zSystems: Rewrite l(g)rl @GOTENT to larl for --no-pie

IBM zSystems: Rewrite l(g)rl @GOTENT to larl for --no-pie

Regtested on s390x-redhat-linux.

Rewriting l(g)rl @GOTENT to larl is unnecessarily guarded by
bfd_link_pic().  There were no use cases for this in the past, but
since recently the Linux Kernel on s390x is compiled with -fPIE
and linked with --no-pie.  Remove the unnecessary bfd_link_pic()
check.

bfd/ChangeLog:

        * elf32-s390.c (elf_s390_relocate_section): Don't check for
	bfd_link_pic() when rewriting lrl@GOTENT to larl.
	(elf_s390_finish_dynamic_symbol): Emit a relative reloc for
	the above case.
        * elf64-s390.c (elf_s390_relocate_section): Don't check for
	bfd_link_pic() when rewriting lgrl@GOTENT to larl.
	(elf_s390_finish_dynamic_symbol): Emit a relative reloc for
	the above case.

ld/ChangeLog:

* testsuite/ld-s390/s390.exp: Hook up the new tests.
        * testsuite/ld-s390/gotreloc_31-no-pie-1.dd: New test.
        * testsuite/ld-s390/gotreloc_64-no-pie-1.dd: New test.