usb: dwc3: Fix warnings on 64-bit builds

Change aritmentics to use 64bit types to be compatible with 64bit
builds.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
diff --git a/drivers/usb/dwc3/io.h b/drivers/usb/dwc3/io.h
index 5042a24..0d9fa22 100644
--- a/drivers/usb/dwc3/io.h
+++ b/drivers/usb/dwc3/io.h
@@ -23,7 +23,7 @@
 #define	CACHELINE_SIZE		CONFIG_SYS_CACHELINE_SIZE
 static inline u32 dwc3_readl(void __iomem *base, u32 offset)
 {
-	u32 offs = offset - DWC3_GLOBALS_REGS_START;
+	unsigned long offs = offset - DWC3_GLOBALS_REGS_START;
 	u32 value;
 
 	/*
@@ -38,7 +38,7 @@
 
 static inline void dwc3_writel(void __iomem *base, u32 offset, u32 value)
 {
-	u32 offs = offset - DWC3_GLOBALS_REGS_START;
+	unsigned long offs = offset - DWC3_GLOBALS_REGS_START;
 
 	/*
 	 * We requested the mem region starting from the Globals address