CVE-2026-68434 serial: 8250_mid: Fix NULL function pointer dereference on DNV/ICX-D/SNR platforms

In the Linux kernel, the following vulnerability has been resolved: serial: 8250mid: Fix NULL function pointer dereference on DNV/ICX-D/SNR platforms Commit b1b4efea05a5 "serial: 8250mid: Disable DMA for selected platforms" replaced the dnvboard setup and exit callbacks with PTRIFfalse, ..., whic...