dmaengine: at_hdmac: Extend the Flow Controller bitfield to three bits

Some chips have two bits (e.g SAMA5D3), and some have three (e.g.
SAM9G45). A field width of three is compatible as long as valid
values are used for the different chips.

There is no current use of any value needing three bits, so the
fixed bug is relatively benign.

Fixes: d8840a7 ("dmaengine: at_hdmac: Use bitfield access macros")
Cc: stable@vger.kernel.org
Reviewed-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Signed-off-by: Peter Rosin <peda@axentia.se>
Link: https://lore.kernel.org/r/e2c898ba-c3a3-5dd3-384b-0585661c79f2@axentia.se
Signed-off-by: Vinod Koul <vkoul@kernel.org>

Author: peda-r

drivers/dma/at_hdmac.c

@@ -132,7 +132,7 @@
 #define ATC_DST_PIP		BIT(12)		/* Destination Picture-in-Picture enabled */
 #define ATC_SRC_DSCR_DIS	BIT(16)		/* Src Descriptor fetch disable */
 #define ATC_DST_DSCR_DIS	BIT(20)		/* Dst Descriptor fetch disable */
-#define ATC_FC			GENMASK(22, 21)	/* Choose Flow Controller */
+#define ATC_FC			GENMASK(23, 21)	/* Choose Flow Controller */
 #define ATC_FC_MEM2MEM		0x0		/* Mem-to-Mem (DMA) */
 #define ATC_FC_MEM2PER		0x1		/* Mem-to-Periph (DMA) */
 #define ATC_FC_PER2MEM		0x2		/* Periph-to-Mem (DMA) */