Enable use of kexec to load the kernel. Applied commits:
- https://github.com/tux-mind/tf201-kernel/commit/026dded24285e3cc6b30103fe13ee7e6c2546e6e
- https://github.com/tux-mind/tf201-kernel/commit/dd05374b0c0a025ca5c96b8030b247c3a9c3fac0
- https://github.com/tux-mind/tf201-kernel/commit/011e19a7c297064948d24e265903821e89130869