Add additional chip ID for an older revision of LTC2978, as well
as two chip IDs for LTC3882. Turns out the LTC3882 does support the
LTC2978_MFR_SPECIAL_ID register, and reading it returns its chip ID,
but the register is undocumented.
Suggested-by: Michael Jones <mike@proclivis.com>
Tested-by: Michael Jones <mike@proclivis.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>