hw/misc/sbsa_ec: Declare QOM macros using OBJECT_DECLARE_SIMPLE_TYPE()

hw/misc/sbsa_ec: Declare QOM macros using OBJECT_DECLARE_SIMPLE_TYPE()

This model was merged few days before the QOM cleanup from
commit 8063396bf3 ("Use OBJECT_DECLARE_SIMPLE_TYPE when possible")
was pulled and merged. Manually adapt.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20230109140306.23161-13-philmd@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>