net: tcp2: Use mutex instead of irq_lock
net: tcp2: Use mutex instead of irq_lock

When needing to lock non-connection related access, use k_mutex
instead of locking irq. There is really no reason to prevent the
system from generating interrupts.

Fixes #30636

Signed-off-by: Jukka Rissanen <f9f077d1da4c7aa947f9864fa5a28c3588f6a45d@linux.intel.com>

finikorg/zephyr,finikorg/zephyr,nashif/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,nashif/zephyr,Vudentz/zephyr,finikorg/zephyr,finikorg/zephyr,nashif/zephyr,zephyrproject-rtos/zephyr,Vudentz/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,Vudentz/zephyr,galak/zephyr,Vudentz/zephyr,galak/zephyr,nashif/zephyr,nashif/zephyr,Vudentz/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,Vudentz/zephyr,galak/zephyr