Add the following attributes to the sysfs ABI.

in[0-*]_average
in[0-*]_lowest
in[0-*]_highest
in[0-*]_reset_history
in_reset_history

curr[1-*]_average
curr[1-*]_lowest
curr[1-*]_highest
curr[1-*]_reset_history
curr_reset_history
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
Reviewed-by: Robert Coulson <robert.coulson@ericsson.com>