This patch adds the essential AArch32 architecture helpers
arch.h and arch_helpers.h and modifies `_types.h` to add AArch32
support.
A new build option `ARCH` is defined in the top level makefile to
enable the component makefiles to choose the right files based on the
Architecture it is being build for. Depending on this flag, either
`AARCH32` or `AARCH64` flag is defined by the Makefile. The default
value of `ARCH` flag is `aarch64`. The AArch32 build support will be
added in a later patch.
Change-Id: I405e5fac02db828a55cd25989b572b64cb005241
* Move stdlib header files from include/stdlib to include/lib/stdlib for
consistency with other library headers.
* Fix checkpatch paths to continue excluding stdlib files.
* Create stdlib.mk to define the stdlib source files and include directories.
* Include stdlib.mk from the top level Makefile.
* Update stdlib header path in the fip_create Makefile.
* Update porting-guide.md with the new paths.
Change-Id: Ia92c2dc572e9efb54a783e306b5ceb2ce24d27fa