juno/xrp7724: Trust the HAL in mod_sensor_driver_api

This driver implements an API defined by the HAL, so
we can be sure that the parameters passed to us do
not need to be sanitized.

Change-Id: Id8d8609b2608ec88ccaa006f946fbfe26d840a0a
Signed-off-by: Nicola Mazzucato <nicola.mazzucato@arm.com>