Staging: mt29f_spinand: Use preferred kernel types

Replace remaining instances of 'uint8_t' with 'u8' for consistency since
'u8' and 'u16' are already being used in other parts of the code.

Replace also 'uint32_t' with 'u32' on the header file.
Checkpatch pointed out this issue.

CHECK: Prefer kernel type 'u8' over 'uint8_t'
CHECK: Prefer kernel type 'u32' over 'uint32_t'

Signed-off-by: Eva Rachel Retuya <eraretuya@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>