staging: rtl8188eu: core: Use put_unaligned_le16

Introduce the use of function put_unaligned_le16.
This is done using the following Coccinelle semantic patch:

//<smpl>
@@ identifier tmp; expression ptr; expression y,e; type T; @@

- tmp = cpu_to_le16(y);

  <+... when != tmp
- memcpy(ptr, (T)&tmp, ...);
+ put_unaligned_le16(y,ptr);
  ...+>
? tmp = e

@@ type T; identifier tmp; @@

- T tmp;
...when != tmp
//</smpl>

Corresponding header file has been added too.

Signed-off-by: Amitoj Kaur Chawla <amitoj1606@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>