lld fails to handle predicated add instructions w/GOT_16_X relocation

[androm3da]

$ echo 'if (p0) r0 = add(r0,##bar@GOT)' | llvm-mc -triple=hexagon -filetype=obj -o out.o
$ ld.lld -shared out.o -o out.so
ld.lld: error: unrecognized instruction for 16_X type: 0x7400C000

[llvmbot]

@llvm/issue-subscribers-backend-hexagon

Author: Brian Cain (androm3da)

``` $ echo 'if (p0) r0 = add(r0,##bar@GOT)' | llvm-mc -triple=hexagon -filetype=obj -o out.o $ ld.lld -shared out.o -o out.so ld.lld: error: unrecognized instruction for 16_X type: 0x7400C000

</details>

[llvmbot]

@llvm/issue-subscribers-lld-elf

Author: Brian Cain (androm3da)

``` $ echo 'if (p0) r0 = add(r0,##bar@GOT)' | llvm-mc -triple=hexagon -filetype=obj -o out.o $ ld.lld -shared out.o -o out.so ld.lld: error: unrecognized instruction for 16_X type: 0x7400C000

</details>