spi/xilinx_spi: fix incorrect casting

This patch fixes the error exposed by the following build warning:

drivers/spi/xilinx_spi.c: In function 'xilinx_spi_init':
drivers/spi/xilinx_spi.c:411: warning: cast from pointer to integer
of different size

Fixed by change %x to %p in the format string.
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

drivers/spi/xilinx_spi.c

@@ -408,8 +408,8 @@ struct spi_master *xilinx_spi_init(struct device *dev, struct resource *mem,
 		goto free_irq;
 	}
 
-	dev_info(dev, "at 0x%08X mapped to 0x%08X, irq=%d\n",
-		(u32)mem->start, (u32)xspi->regs, xspi->irq);
+	dev_info(dev, "at 0x%08llX mapped to 0x%p, irq=%d\n",
+		(unsigned long long)mem->start, xspi->regs, xspi->irq);
 	return master;
 
 free_irq: