Merge Pull Request from: @xiexiuqi 
 
Add OPENEULER_VERSION_CODE to version.h, so modules or applications
can identify the specific kernel version.

The version information is generated in "linux/version.h", as bellow:
include/generated/uapi/linux/version.h

 #define OPENEULER_MAJOR 2203                    // openEuler 22.03
 #define OPENEULER_MINOR 1                       // SP1
 #define OPENEULER_VERSION(a,b) (((a) << 8) + (b))
 #define OPENEULER_VERSION_CODE 563969 
 
Link:https://gitee.com/openeuler/kernel/pulls/195 
Reviewed-by: Zheng Zengkai <zhengzengkai@huawei.com> 
Reviewed-by: Laibin Qiu <qiulaibin@huawei.com> 
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>