docs: ABI: drop two duplicate symbols

docs: ABI: drop two duplicate symbols

As warned by get_abi.py, there are two symbols that are
defined twice:

WARNING: /sys/devices/system/cpu/cpuX/topology/physical_package_id is defined 2 times: \
	/new_devel/v4l/docs/Documentation/ABI/stable/sysfs-devices-system-cpu:27; \
	/new_devel/v4l/docs/Documentation/ABI/testing/sysfs-devices-system-cpu:70
WARNING: /sys/devices/system/cpu/cpuX/topology/ppin is defined 2 times: \
	/new_devel/v4l/docs/Documentation/ABI/stable/sysfs-devices-system-cpu:89; \
	/new_devel/v4l/docs/Documentation/ABI/testing/sysfs-devices-system-cpu:70

As the documentation at testing/sysfs-devices-system-cpu, drop
the duplicated one from stable.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/c3dce809f577584cf9aedafc6c2a0d5a9ca909ac.1739394480.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>