Build: Add IAR support to new build system

Adding IAR toolchain cmake file and target files for
an519, an521, musca_a, sse-200_aws, psoc64, lpcxpresso55s69

Updated a few files to discriminate between armclang/gcc and iar

Removed some dead files

Add patch file to mbedcrypto - this can be removed once the PR with the
same changes is merged upstream

Signed-off-by: Raef Coles <raef.coles@arm.com>
Signed-off-by: TTornblom <thomas.tornblom@iar.com>
Change-Id: I2aafff7803d0aa12f1df598b8f157e94e1f3c03f
19 files changed