iio: adc: mcp3911: use correct id bits

The device ID should be shifted 6 bits to left according to datasheet.

Fixes: 3a89b289 ("iio: adc: add support for mcp3911")
Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
Link: https://lore.kernel.org/r/20221010194641.676484-1-marcus.folkesson@gmail.comSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/adc/mcp3911.c

@@ -55,8 +55,8 @@
 /* Internal voltage reference in mV */
 #define MCP3911_INT_VREF_MV		1200
 
-#define MCP3911_REG_READ(reg, id)	((((reg) << 1) | ((id) << 5) | (1 << 0)) & 0xff)
-#define MCP3911_REG_WRITE(reg, id)	((((reg) << 1) | ((id) << 5) | (0 << 0)) & 0xff)
+#define MCP3911_REG_READ(reg, id)	((((reg) << 1) | ((id) << 6) | (1 << 0)) & 0xff)
+#define MCP3911_REG_WRITE(reg, id)	((((reg) << 1) | ((id) << 6) | (0 << 0)) & 0xff)
 
 #define MCP3911_NUM_CHANNELS		2