Fix amdllpc -gfxip option parsing
Fix amdllpc -gfxip option parsing

This fixes it so that unspecified parts of the version are assumed to be
zero, so e.g. -gfxip=9 means 9.0.0. Previously it meant 9.0.2, because
of information leaking through from the default value of 8.0.2.

GPUOpen-Drivers/llpc,googlestadia/llpc,googlestadia/llpc,googlestadia/llpc,GPUOpen-Drivers/llpc,GPUOpen-Drivers/llpc,GPUOpen-Drivers/llpc,GPUOpen-Drivers/llpc,googlestadia/llpc,googlestadia/llpc