picolibc: Add patch allowing use of crt0

A couple of Zephyr modules build against the library crt0. This patch
makes that work when picolibc is not the default toolchain C libary.

Signed-off-by: Keith Packard <keithp@keithp.com>
Signed-off-by: Anas Nashif <anas.nashif@intel.com>

Author: keith-packard