tic6x: Call _bfd_elf_add_dynamic_tags

Update tic6x linker tests to expect C6000_DSBT_BASE, C6000_DSBT_SIZE and
C6000_DSBT_INDEX dynamic tags immediately before NULL dynamic tag.

bfd/

	* elf32-tic6x.c (elf32_tic6x_size_dynamic_sections): Call
	_bfd_elf_add_dynamic_tags.

ld/

	* testsuite/ld-tic6x/shlib-1.rd: Move C6000_DSBT_BASE,
	C6000_DSBT_SIZE and C6000_DSBT_INDEX dynamic tags to the last.
	* testsuite/ld-tic6x/shlib-1b.rd: Likewise.
	* testsuite/ld-tic6x/shlib-1r.rd: Likewise.
	* testsuite/ld-tic6x/shlib-1rb.rd: Likewise.
	* testsuite/ld-tic6x/shlib-app-1.rd: Likewise.
	* testsuite/ld-tic6x/shlib-app-1b.rd: Likewise.
	* testsuite/ld-tic6x/shlib-app-1r.rd: Likewise.
	* testsuite/ld-tic6x/shlib-app-1rb.rd: Likewise.
	* testsuite/ld-tic6x/shlib-noindex.rd: Likewise.
	* testsuite/ld-tic6x/static-app-1.rd: Likewise.
	* testsuite/ld-tic6x/static-app-1b.rd: Likewise.
	* testsuite/ld-tic6x/static-app-1r.rd: Likewise.
	* testsuite/ld-tic6x/static-app-1rb.rd: Likewise.