hwmon: (max16065) Fix alarm attributes

Chips reporting overcurrent alarms report it in the second alarm register.
That means the second alarm register has to be read, even if the chip only
supports 8 or fewer ADC channels.

MAX16067 and MAX16068 report undervoltage and overvoltage alarms in
separate registers. Fold register contents together to report both with
the existing alarm attribute. This requires actually storing the chip type
in struct max16065_data. Rename the variable 'chip' to match the variable
name used in the probe function.

Reviewed-by: Tzung-Bi Shih <tzungbi@kernel.org>
Fixes: f5bae264 ("hwmon: Driver for MAX16065 System Manager and compatibles")
Signed-off-by: Guenter Roeck <linux@roeck-us.net>