I've uncovered an issue with the overlay https://github.com/beagleboard/BeagleBoard-DeviceTrees/blob/v5.10.x-ti-unified/src/arm64/overlays/BBAI64-CSI1-imx219.dts
After studying the BeagleBone schematic and the RPi connector pinout, I believe the V25 pin GPIO signal needs be used to provide the Enable signal on the Raspberry Pi CSI1 connector.

From the BBAI64-CSI1-imx219.dts file:
&main_pmx0 {
csi1_gpio_pins_default: csi1-gpio-pins-default {
pinctrl-single,pins = <
//J721E_IOPAD(0x198, PIN_OUTPUT, 7) /* (V25) RGMII6_TD1.GPIO0_101 /
J721E_IOPAD(0x1b0, PIN_OUTPUT, 7) / (W24) RGMII6_RD1.GPIO0_107 */
>;
};
};