default or selected kernelversion does not have config value CONFIG_VIDEO_BCM2835_UNICAM.
Result is shown for kernelversion 6.10-rc5

Broadcom BCM283x/BCM271x Unicam video capture driver

modulename: bcm2835-unicam.ko


Linux Kernel Configuration
└─>Device Drivers
└─>Multimedia support
└─>Media drivers
└─>Media platform devices
└─>Broadcom BCM283x/BCM271x Unicam video capture driver
Say Y here to enable support for the BCM283x/BCM271x CSI-2 receiver.
This is a V4L2 driver that controls the CSI-2 receiver directly,
independently from the VC4 firmware.

This driver is mutually exclusive with the use of bcm2835-camera. The
firmware will disable all access to the peripheral from within the
firmware if it finds a DT node using it, and bcm2835-camera will
therefore fail to probe.

To compile this driver as a module, choose M here. The module will be
called bcm2835-unicam.

source code: