soccr.h: use uint32_t instead of __u32

As uint32_t already has occupied the header, use it for all 32-bit
unsigns. That will allow to drop additional include <linux/types.h>.

Signed-off-by: Dmitry Safonov <dsafonov@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>