riscv: Ignore Image.* and loader.bin

Do not track all compressed Image and loader.bin.
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

arch/riscv/boot/.gitignore

 # SPDX-License-Identifier: GPL-2.0-only
 Image
-Image.gz
+Image.*
 loader
 loader.lds
+loader.bin