hwmon: (tmp421) report /PVLD condition as fault

hwmon: (tmp421) report /PVLD condition as fault

[ Upstream commit 540effa7f283d25bcc13c0940d808002fee340b8 ]

For both local and remote sensors all the supported ICs can report an
"undervoltage lockout" condition which means the conversion wasn't
properly performed due to insufficient power supply voltage and so the
measurement results can't be trusted.

Fixes: 49fec4ff7c2b ("hwmon: Add driver for Texas Instruments TMP421/422/423 sensor chips")
Signed-off-by: Paul Fertser <fercerpav@gmail.com>
Link: https://lore.kernel.org/r/20210924093011.26083-2-fercerpav@gmail.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>