Following docs/devel/style.rst guidelines, rename
omap_intr_handler_s -> OMAPIntcState. This also remove a
use of 'struct' in the DECLARE_INSTANCE_CHECKER() macro call.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20230109140306.23161-7-philmd@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>