arch: arm: cmse: re-introduce workaround for typeof

The GNU ARM Embedded "8-2019-q3-update" toolchain
erroneously uses "typeof" instead of "__typeof__".
To work around this we define typeof to be able to
support it.

This reverts commit 01a71eae.

Signed-off-by: Ioannis Glaropoulos <Ioannis.Glaropoulos@nordicsemi.no>