ARM: move AES typedefs and function prototypes to separate header

Put the struct definitions for AES keys and the asm function prototypes in a
separate header and export the asm functions from the module.
This allows other drivers to use them directly.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

idea is taken here - https://github.com/savoca/furnace_kernel_lge_mako/commit/6f371569b5b4a1426bc56c565e2f8df106f4bf36