MAINTAINERS: Fix 'W:' prefix in Invensense IMU entry

The colon is missing, which can confuse scripts/parse-maintainers.pl.
Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Link: https://lore.kernel.org/r/20201108013738.1410528-1-j.neuschaefer@gmx.netSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

MAINTAINERS

@@ -9056,7 +9056,7 @@ INVENSENSE ICM-426xx IMU DRIVER
 M:	Jean-Baptiste Maneyrol <jmaneyrol@invensense.com>
 L:	linux-iio@vger.kernel.org
 S:	Maintained
-W	https://invensense.tdk.com/
+W:	https://invensense.tdk.com/
 F:	Documentation/devicetree/bindings/iio/imu/invensense,icm42600.yaml
 F:	drivers/iio/imu/inv_icm42600/