spi: dw-mmio: add error handling for reset_control_deassert()

Currently reset_control_deassert() is called without checking its
return value. This can lead to silent failures when reset deassertion
fails.

Add proper error handling to:
1. Check the return value of reset_control_deassert()
2. Return the error to the caller
3. Provide meaningful error message using dev_err_probe()

This ensures that reset-related failures are properly reported during
probe and helps with debugging reset issues.

Signed-off-by: Artem Shimko <a.shimko.dev@gmail.com>
Link: https://patch.msgid.link/20251007101134.1912895-1-a.shimko.dev@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>

Author: Artem Shimko

drivers/spi/spi-dw-mmio.c

@@ -358,7 +358,9 @@ static int dw_spi_mmio_probe(struct platform_device *pdev)
 	if (IS_ERR(dwsmmio->rstc))
 		return PTR_ERR(dwsmmio->rstc);
 
-	reset_control_deassert(dwsmmio->rstc);
+	ret = reset_control_deassert(dwsmmio->rstc);
+	if (ret)
+		return dev_err_probe(&pdev->dev, ret, "Failed to deassert resets\n");
 
 	dws->bus_num = pdev->id;