Enforcing CC_DIR to be set

To make this work when used with FVP and OP-TEE we need to make sure
CC_DIR has been set before calling this script.

Update etc/profile also so the command ll is working.
Vexpress: Enforcing CC_DIR to be set

To make this work when used with QEMU and OP-TEE we need to make sure
CC_DIR has been set before calling this script.