usb: dwc3: remove unused struct member dwc3->mem

Member @mem in struct dwc3 is not used in any places. Clean up it.
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

drivers/usb/dwc3/core.c

@@ -941,7 +941,6 @@ static int dwc3_probe(struct platform_device *pdev)
 		return -ENOMEM;
 
 	dwc = PTR_ALIGN(mem, DWC3_ALIGN_MASK + 1);
-	dwc->mem = mem;
 	dwc->dev = dev;
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

drivers/usb/dwc3/core.h

@@ -784,7 +784,6 @@ struct dwc3_scratchpad_array {
  * @ep0state: state of endpoint zero
  * @link_state: link state
  * @speed: device speed (super, high, full, low)
- * @mem: points to start of memory which is used for this struct.
  * @hwparams: copy of hwparams registers
  * @root: debugfs root folder pointer
  * @regset: debugfs pointer to regdump file
@@ -934,8 +933,6 @@ struct dwc3 {
 	u8			num_out_eps;
 	u8			num_in_eps;
 
-	void			*mem;
-
 	struct dwc3_hwparams	hwparams;
 	struct dentry		*root;
 	struct debugfs_regset32	*regset;