iio: hid-sensors: Fix compilation warning

Move the 'static' keyword to beginning of definition to silence the
following compilation warning:
drivers/iio/common/hid-sensors/hid-sensor-attributes.c:34:1: warning: ‘static’ is not at beginning of declaration [-Wold-style-declaration]

Signed-off-by: Sachin Kamat <sachin.kamat@samsung.com>
Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>