hwmon: (amd_energy) modify the visibility of the counters

This patch limits the visibility to owner and groups only for the
energy counters exposed through the hwmon based amd_energy driver.

Cc: stable@vger.kernel.org
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Naveen Krishna Chatradhi <nchatrad@amd.com>
Link: https://lore.kernel.org/r/20201112172159.8781-1-nchatrad@amd.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
