Add linux type definitions, because there are many types
(eg. u8/u16/u64) used in UBIFS linux kernel libs. Besides
move type conversions (eg. cpu_to_le16, cpu_to_le32, etc.)
into type definitions header file.
This is a preparation for replacing implementation of UBIFS utils with
linux kernel libs.
Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com> Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>