MIPS/LD/testsuite: Correct relocation addends in VxWorks tests

Fix commit 171191ba ("Add support for STT_IFUNC"),
<https://sourceware.org/ml/binutils/2008-12/msg00052.html>, commit
e04d7088 ("PR ld/14088: Always display addend as signed hex
number"), <https://sourceware.org/ml/binutils/2012-05/msg00123.html> and
commit 343dbc36 ("Print addend as signed in objdump"),
<https://sourceware.org/ml/binutils/2012-05/msg00163.html> regressions:

FAIL: VxWorks executable test 1 (dynamic)
FAIL: ld-mips-elf/vxworks-forced-local-1

seen with `mips-vxworks' and `mipsel-vxworks' targets and adjust dump
patterns according to changes made to the presentation of relocation
addends in `readelf -r' and `objdump -r' output.

	ld/
	* testsuite/ld-mips-elf/vxworks-forced-local-1.d: Correct the
	presentation of relocation addends.
	* testsuite/ld-mips-elf/vxworks1-lib.rd: Likewise.
	* testsuite/ld-mips-elf/vxworks1.dd: Likewise.
	* testsuite/ld-mips-elf/vxworks1.rd: Likewise.