configs: enable SYSRESET_SBI on qemu-riscvXX_smode_defconfig

There should be a platform compiled with the new driver.

Enable CONFIG_SYSRESET_SBI for all QEMU boards using SBI.

If you want to test the SBI sysreset driver, disable
CONFIG_SYSRESET_SYSCON.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Leo Yu-Chi Liang <ycliang@andestech.com>