fsp: Move and rename fsp_types.h file

The fsp_types.h header file contains macros for building signatures of
different widths. These signature macros are architecture agnostic,
and can be used in all places which use signatures in a data
structure. Move and rename the fsp_types.h under the common include
header.

Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>