You won't be able to renew your GMC Yukon's registration until the DMV mails out the renewal form. Typically this occurs 2-3 months before the vehicle's registration expiration date. You can obtain a smog check anytime but since the smog certificate is only valid for 90 days, this to will not suffice for your purposes.
The best thing to do here is to use the DMV's Statement of Facts form. When your Yukon's registration renewal form arrives to the address on file in California, fill out and sign DMV's "Statement of Facts" form (Section G), OR complete Reg 5103, explaining your vehicle is in Texas (or out-of-state) and the registration tags will be mailed to the registration address on file with the DMV, without needing a smog check.
You'll need a physical address in California, so hopefully you are not giving up your current address. If you are leaving California (moving out of your current address) you'll need to either obtain a California P.O. Box (which you'll need to update with the DMV) or give up your vehicle's California registration and register your GMC Yukon in Texas, and in accordance with Texas emission requirements.
Mail the form to:
Department of Motor Vehicles
P.O. Box 942869
Sacramento, CA 94269-0001
You may download the Statement of Facts Form (Reg 256) here, and Temporary Smog Exemption Form (Reg 5103) here.
For more information visit... How to register my car in California without a smog check when it is temporarily located out of state.