linux-gbmc: Backport adm1273 and adm1281 support

ref: https://github.com/torvalds/linux/blob/master/drivers/hwmon/pmbus/adm1275.c

Tested:
hotswap_in       | 11.79 Amps        | ok
hotswap_in       | 555.50 Watts      | ok
hotswap_in       | 29 degrees C      | ok
hotswap_in       | 47.91 Volts       | ok

Fusion-Link: N/A, no fusion2 link
Platforms-Affected: platform21 as it is only using this brancg
Smoke-Bug-Id: 418641065
Google-Bug-Id: 418934313
Change-Id: I37d125435803163dcba5a50745303d7aaf8a5e15
Signed-off-by: Charles Hsu <charles.hsu@quanta.corp-partner.google.com>
(cherry picked from commit b039dd52a6fb9990c6af8136d3e1a093870c9c58)