dmaengine: sh: rz-dmac: add r7s72100 support

This SoC needs to make getting resets optional. Descriptions are
reworded to be more generic.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20241007110200.43166-8-wsa+renesas@sang-engineering.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

drivers/dma/sh/Kconfig

@@ -49,10 +49,10 @@ config RENESAS_USB_DMAC
 	  SoCs.
 
 config RZ_DMAC
-	tristate "Renesas RZ/{G2L,V2L} DMA Controller"
-	depends on ARCH_RZG2L || COMPILE_TEST
+	tristate "Renesas RZ DMA Controller"
+	depends on ARCH_R7S72100 || ARCH_RZG2L || COMPILE_TEST
 	select RENESAS_DMA
 	select DMA_VIRTUAL_CHANNELS
 	help
-	  This driver supports the general purpose DMA controller found in the
-	  Renesas RZ/{G2L,V2L} SoC variants.
+	  This driver supports the general purpose DMA controller typically
+	  found in the Renesas RZ SoC variants.

drivers/dma/sh/rz-dmac.c

@@ -893,7 +893,7 @@ static int rz_dmac_probe(struct platform_device *pdev)
 	/* Initialize the channels. */
 	INIT_LIST_HEAD(&dmac->engine.channels);
 
-	dmac->rstc = devm_reset_control_array_get_exclusive(&pdev->dev);
+	dmac->rstc = devm_reset_control_array_get_optional_exclusive(&pdev->dev);
 	if (IS_ERR(dmac->rstc))
 		return dev_err_probe(&pdev->dev, PTR_ERR(dmac->rstc),
 				     "failed to get resets\n");