build: remove unused linux related code

- Modules are not a feature of the Zephyr kernel.
- genksyms removed, not used by zephyr
- bin2c remove, not used in zephyr

Change-Id: Ic8f0e786530dcf410b07d6c5cc47f1087000d528
Signed-off-by: Anas Nashif <anas.nashif@intel.com>