dmaengine: at_xdmac: Remove unused inline function at_xdmac_csize()

commit 765c37d8 ("dmaengine: at_xdmac: rework slave configuration part")
left behind this, so can remove it.
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Reviewed-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Link: https://lore.kernel.org/r/20210407132543.23652-1-yuehaibing@huawei.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

drivers/dma/at_xdmac.c

@@ -344,17 +344,6 @@ static inline int at_xdmac_chan_is_paused(struct at_xdmac_chan *atchan)
 	return test_bit(AT_XDMAC_CHAN_IS_PAUSED, &atchan->status);
 }
 
-static inline int at_xdmac_csize(u32 maxburst)
-{
-	int csize;
-
-	csize = ffs(maxburst) - 1;
-	if (csize > 4)
-		csize = -EINVAL;
-
-	return csize;
-};
-
 static inline bool at_xdmac_chan_is_peripheral_xfer(u32 cfg)
 {
 	return cfg & AT_XDMAC_CC_TYPE_PER_TRAN;