fix(deps): add missing aeabi_memset.S

This file provides __aeabi_memclr8 builtin which the Ubuntu 22.04
version of clang 14 needs to compile. Add it to prevent this oddity from
failing the build.

Signed-off-by: Boyan Karatotev <boyan.karatotev@arm.com>
Change-Id: Id67aa0abba4a27c51b3ed6bb1be84b4e803b44bf