iio:adc:mcp3422 Fix incorrect scales table

This patch fixes uncorrect order of mcp3422_scales table, the values
was erroneously transposed.
It removes also an unused array and a wrong comment.
Signed-off-by: Angelo Compagnucci <angelo.compagnucci@gmail.com>
Cc: Stable@vger.kernel.org
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

drivers/iio/adc/mcp3422.c

@@ -58,20 +58,11 @@
 		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SAMP_FREQ), \
 	}
 
-/* LSB is in nV to eliminate floating point */
-static const u32 rates_to_lsb[] = {1000000, 250000, 62500, 15625};
-
-/*
- *  scales calculated as:
- *  rates_to_lsb[sample_rate] / (1 << pga);
- *  pga is 1 for 0, 2
- */
-
 static const int mcp3422_scales[4][4] = {
-	{ 1000000, 250000, 62500, 15625 },
-	{ 500000 , 125000, 31250, 7812 },
-	{ 250000 , 62500 , 15625, 3906 },
-	{ 125000 , 31250 , 7812 , 1953 } };
+	{ 1000000, 500000, 250000, 125000 },
+	{ 250000 , 125000, 62500 , 31250  },
+	{ 62500  , 31250 , 15625 , 7812   },
+	{ 15625  , 7812  , 3906  , 1953   } };
 
 /* Constant msleep times for data acquisitions */
 static const int mcp3422_read_times[4] = {