Yes, it's fine:

Exception No. 2: Receptacles installed to provide power for supplemental equipment and lighting on gas-fired ranges, ovens, or counter-mounted cooking units.

BTW: the power is also most likely used for the ignitors.

Actually in many cooktops these days it's more than that. The amount of wiring in my professional series is staggering. It not only lights the burners but it cuts off the igniters when the burners are lit, cuts off the gas if the burners don't light, and cycle two of the burners on and off to bet an extra low simmer.