CVE ID:	CVE-2023-52627
Description:	In the Linux kernel, the following vulnerability has been resolved: iio: adc: ad7091r: Allow users to configure device events AD7091R-5 devices are supported by the ad7091r-5 driver together with the ad7091r-base driver. Those drivers declared iio events for notifying user space when ADC readings fall bellow the thresholds of low limit registers or above the values set in high limit registers. However, to configure iio events and their thresholds, a set of callback functions must be implemented and those were not present until now. The consequence of trying to configure ad7091r-5 events without the proper callback functions was a null pointer dereference in the kernel because the pointers to the callback functions were not set. Implement event configuration callbacks allowing users to read/write event thresholds and enable/disable event generation. Since the event spec structs are generic to AD7091R devices, also move those from the ad7091r-5 driver the base driver so they can be reused when support for ad7091r-2/-4/-8 be added.
Test IDs:	None available
Cross References:	Common Vulnerability Exposure (CVE) ID: CVE-2023-52627 https://git.kernel.org/stable/c/020e71c7ffc25dfe29ed9be6c2d39af7bd7f661f https://git.kernel.org/stable/c/020e71c7ffc25dfe29ed9be6c2d39af7bd7f661f https://git.kernel.org/stable/c/137568aa540a9f587c48ff7d4c51cdba08cfe9a4 https://git.kernel.org/stable/c/137568aa540a9f587c48ff7d4c51cdba08cfe9a4 https://git.kernel.org/stable/c/1eba6f7ffa295a0eec098c107043074be7cc4ec5 https://git.kernel.org/stable/c/1eba6f7ffa295a0eec098c107043074be7cc4ec5 https://git.kernel.org/stable/c/49f322ce1f265935f15e5512da69a399f27a5091 https://git.kernel.org/stable/c/49f322ce1f265935f15e5512da69a399f27a5091 https://git.kernel.org/stable/c/55aca2ce91a63740278502066beaddbd841af9c6 https://git.kernel.org/stable/c/55aca2ce91a63740278502066beaddbd841af9c6 https://git.kernel.org/stable/c/89c4e63324e208a23098f7fb15c00487cecbfed2 https://git.kernel.org/stable/c/89c4e63324e208a23098f7fb15c00487cecbfed2