aws-iot-example: Add provisioning data to binary

The keyCLIENT_CERTIFICATE_PEM, keyCLIENT_PRIVATE_KEY_PEM
and keyJITR_DEVICE_CERTIFICATE_AUTHORITY_PEM macros are used
in the new provisioning binary. They are loaded into a predefined
address and the dev_mode_key_provisioning.c can use it directly.

Signed-off-by: Bence Balogh <bence.balogh@arm.com>