drivers: usb: fsl: Define usb control register mask for w1c bits

Define and use CONTROL_REGISTER_W1C_MASK to make sure that
w1c bits of usb control register do not get reset while
writing any other bit

Signed-off-by: Nikhil Badola <nikhil.badola@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/host/ehci-fsl.h

@@ -52,6 +52,7 @@
 #define SNOOP_SIZE_2GB		0x1e
 
 /* control Register Bit Masks */
+#define CONTROL_REGISTER_W1C_MASK       0x00020000  /* W1C: PHY_CLK_VALID */
 #define ULPI_INT_EN             (1<<0)
 #define WU_INT_EN               (1<<1)
 #define USB_CTRL_USB_EN         (1<<2)