tests/qtest: Add testcase for BCM2835 BSC

Simple testcase for validating proper operation of read and write for all
three BSC controllers.

Signed-off-by: Rayhan Faizel <rayhan.faizel@gmail.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 20240224191038.2409945-4-rayhan.faizel@gmail.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2 files changed