Yes, you can boot from the CM4 core. You can refer to chapter 2.2 from this application note: https://www.nxp.com/docs/en/application-note/AN13264.pdf
As NXP official SDK package only supports CM7 as main core (boot core), the enablement for this case is limited. Do not switch to CM4 as main core if it is not a must in your application.
If you have more questions do not hesitate to ask me.
Best regards,
Omar