Turris Omnia MCU ECDSA message signing

configname: CONFIG_TURRIS_OMNIA_MCU_KEYCTL

Linux Kernel Configuration
└─>Device Drivers
└─>Platform support for CZ.NIC's Turris hardware
└─>Turris Omnia MCU ECDSA message signing
In linux kernel since version 6.1.145 (release Date: 2025-07-14)  
Say Y here to add support for ECDSA message signing with board private
key (if available on the MCU). This is exposed via the keyctl()
syscall.