Fixes for Xcode 5 and OSX 10.9.
kernel.mk: Put elf.h into the include path on Darwin builds.

Change-Id: I7069b956965d27caac3b2e4c3cc2e8b4c1da7a82
Merge commit 'e5bdddf18ce2b28d4b9ced32413f54d96840e01e' into cm-10.1