iio: inv-mpu: Specify the expected format/precision for write channels
iio: inv-mpu: Specify the expected format/precision for write channels

The gyroscope needs IIO_VAL_INT_PLUS_NANO for the scale channel and
unless specified write returns MICRO by default.
This needs to be properly specified so that write operations into scale
have the expected behaviour.

Signed-off-by: Adriana Reus <54192c763ae4f960dbf2b2f913f2990b3167a436@intel.com>
Cc: <d96e5b2dd07c1733b2b013bd82922c22baade37d@vger.kernel.org>
Signed-off-by: Jonathan Cameron <09f65b71b7655725897b2fd41a09a0cefe2e1ace@kernel.org>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs