test/qtest: Introduce a new aspeed-smc-utils.c to place common testcases

test/qtest: Introduce a new aspeed-smc-utils.c to place common testcases

The testcases for ASPEED SMC model were placed in aspeed_smc-test.c.
However, this test file only supports for ARM32. To support all ASPEED SOCs
such as AST2700 whose CPU architecture is aarch64, introduces a new
aspeed-smc-utils source file and move all common APIs and testcases
from aspeed_smc-test.c to aspeed-smc-utils.c.

Finally, users are able to re-used these testcase for AST2700 and future
ASPEED SOCs testing.

Signed-off-by: Jamin Lin <jamin_lin@aspeedtech.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Link: https://lore.kernel.org/r/20241127091543.1243114-10-jamin_lin@aspeedtech.com
Signed-off-by: Cédric Le Goater <clg@redhat.com>