gdb/testsuite: fix gdb.rocm/code-object-load-while-breakpoint-hit.exp with native-gdbserver

ROCm tests don't work under the native-gdbserver board, but switch it to
use the new -inferior-args option anyway, to give the good example.

Change-Id: I684cd5e4328e033072735d5feca8037ca77b57c1
Reviewed-By: Tankut Baris Aktemur <TankutBaris.Aktemur@amd.com>