timer: APIC timer count is a lock free accessor
timer: APIC timer count is a lock free accessor

Selects the hidden Kconfig to note that the APIC timer's cycle count
accessor is a lock free path and may use the spin lock time limit check.

Signed-off-by: Tom Burdick <63c280986e32082c9e27a1a69ac8b19e3d0c6b4b@intel.com>

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