SPI-SD adapter should be usable, even without any SD card
wired. Refactor test_riscv64_sifive_u_mmc_spi() to make it
more generic and add another test, inspired by this report:
https://lore.kernel.org/qemu-devel/5b2dc427-f0db-4332-a997-fe0c82415acd@roeck-us.net/
Inspired-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Gustavo Romero <gustavo.romero@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Tested-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20250812140415.70153-3-philmd@linaro.org>