A number of the gfx8 cases were the same.  Clean them
up.
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
                        f2g = &gfx_v8_kfd2kgd;
                break;
        case CHIP_FIJI:
-               gfx_target_version = 80003;
-               f2g = &gfx_v8_kfd2kgd;
-               break;
        case CHIP_POLARIS10:
                gfx_target_version = 80003;
                f2g = &gfx_v8_kfd2kgd;
                break;
        case CHIP_POLARIS11:
-               gfx_target_version = 80003;
-               if (!vf)
-                       f2g = &gfx_v8_kfd2kgd;
-               break;
        case CHIP_POLARIS12:
-               gfx_target_version = 80003;
-               if (!vf)
-                       f2g = &gfx_v8_kfd2kgd;
-               break;
        case CHIP_VEGAM:
                gfx_target_version = 80003;
                if (!vf)