footprint: Add Hearing Access Hearing Aid BT Audio sample
footprint: Add Hearing Access Hearing Aid BT Audio sample

Add the hearing aid sample to the footprint tracking for the
nrf52840dk_nrf52840 and nrf5340dk_nrf5340_cpuapp.

The sample should represent a simple hearing aid implementation,
and is thus a very good candidate for tracking the footprint
of LE Audio in Zephyr.

Signed-off-by: Emil Gydesen <a20314356615223738233ab4c4eb1cd8cd4146fa@nordicsemi.no>

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