staging: dwc2: validate the value for phy_utmi_width

The HWCFG4 register stores the supported utmi width values (8, 16 or
both). This commit reads that value and validates the configured value
against that.

If no (valid) value is given, the parameter defaulted to 8 bits
previously.  However, the documentation for dwc2_core_params_struct
suggests that the default should have been 16. Also, the pci bindings
explicitely set the value to 16, so this commit changes the default to
16 bits (if supported, 8 bits otherwise).

With the default changed, the value set in pci.c is changed to -1 to
make it autodetected as well.

Signed-off-by: Matthijs Kooijman <matthijs@stdin.nl>
Acked-by: Paul Zimmerman <paulz@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/staging/dwc2/hw.h b/drivers/staging/dwc2/hw.h
index fafdc19..9c92a3c 100644
--- a/drivers/staging/dwc2/hw.h
+++ b/drivers/staging/dwc2/hw.h
@@ -302,6 +302,9 @@
 #define GHWCFG4_NUM_DEV_MODE_CTRL_EP_SHIFT	16
 #define GHWCFG4_UTMI_PHY_DATA_WIDTH_MASK	(0x3 << 14)
 #define GHWCFG4_UTMI_PHY_DATA_WIDTH_SHIFT	14
+#define GHWCFG4_UTMI_PHY_DATA_WIDTH_8		0
+#define GHWCFG4_UTMI_PHY_DATA_WIDTH_16		1
+#define GHWCFG4_UTMI_PHY_DATA_WIDTH_8_OR_16	2
 #define GHWCFG4_XHIBER				(1 << 7)
 #define GHWCFG4_HIBER				(1 << 6)
 #define GHWCFG4_MIN_AHB_FREQ			(1 << 5)