dw_dmac: fix constant in the comment

Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: NViresh Kumar <viresh.linux@gmail.com>
Signed-off-by: NVinod Koul <vinod.koul@linux.intel.com>

drivers/dma/dw_dmac_regs.h

@@ -82,7 +82,7 @@ struct dw_dma_regs {
 	DW_REG(ID);
 	DW_REG(TEST);
 
-	/* optional encoded params, 0x3c8..0x3 */
+	/* optional encoded params, 0x3c8..0x3f7 */
 };
 
 /* Bitfields in CTL_LO */