staging: comedi: ni_tio.h: tidy up struct ni_gpct

Fix the checkpatch.pl issues:
WARNING: Prefer 'unsigned int' to bare use of 'unsigned'
CHECK: Prefer kernel type 'u64' over 'uint64_t'
CHECK: spinlock_t definition without comment

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/drivers/ni_tio.h

@@ -106,11 +106,11 @@ enum ni_gpct_variant {
 
 struct ni_gpct {
 	struct ni_gpct_device *counter_dev;
-	unsigned counter_index;
-	unsigned chip_index;
-	uint64_t clock_period_ps;	/* clock period in picoseconds */
+	unsigned int counter_index;
+	unsigned int chip_index;
+	u64 clock_period_ps;	/* clock period in picoseconds */
 	struct mite_channel *mite_chan;
-	spinlock_t lock;
+	spinlock_t lock;	/* protects 'mite_chan' */
 };
 
 struct ni_gpct_device {