dmaengine: lgm: use sg_nents_for_dma() helper

Instead of open coded variant let's use recently introduced helper.

Reviewed-by: Bjorn Andersson <andersson@kernel.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://patch.msgid.link/20260108105619.3513561-8-andriy.shevchenko@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

Author: andy-shev

drivers/dma/lgm/lgm-dma.c

@@ -1164,21 +1164,16 @@ ldma_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
 	struct dw2_desc *hw_ds;
 	struct dw2_desc_sw *ds;
 	struct scatterlist *sg;
-	int num = sglen, i;
 	dma_addr_t addr;
+	int num, i;
 
 	if (!sgl)
 		return NULL;
 
 	if (d->ver > DMA_VER22)
 		return ldma_chan_desc_cfg(chan, sgl->dma_address, sglen);
 
-	for_each_sg(sgl, sg, sglen, i) {
-		avail = sg_dma_len(sg);
-		if (avail > DMA_MAX_SIZE)
-			num += DIV_ROUND_UP(avail, DMA_MAX_SIZE) - 1;
-	}
-
+	num = sg_nents_for_dma(sgl, sglen, DMA_MAX_SIZE);
 	ds = dma_alloc_desc_resource(num, c);
 	if (!ds)
 		return NULL;