hwmon: (lm90) Add support for TI TMP451

TI TMP451 is mostly compatible with ADT7461, except for
local temperature low byte and max conversion rate.
Add support to the LM90 driver.

Signed-off-by: Wei Ni <wni@nvidia.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>