iio: pressure: bmp280: fix datasheet links

Updated links for BMP280 and BME280 datasheets on Bosch website.
Datasheet of BMP180 is no longer available on the manufacturer's website,
changed the link to a copy hosted by a third party.

Reported-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Angel Iglesias <ang.iglesiasg@gmail.com>
Link: https://lore.kernel.org/r/20220912222645.377874-1-ang.iglesiasg@gmail.com


Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>