usb: dwc3: make LPM configurable in DT

This patch removes "Enable USB3 LPM Capability" option from Kconfig
and adds snps,usb3_lpm_capable devicetree property instead of it.

USB3 LPM (Link Power Management) capability is hardware property, and
it's platform dependent, so if our hardware supports this feature, we
want rather to configure it in devicetree than having it as Kconfig option.

Signed-off-by: Robert Baldyga <r.baldyga@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
diff --git a/drivers/usb/dwc3/platform_data.h b/drivers/usb/dwc3/platform_data.h
index a3a3b6d..a2bd464 100644
--- a/drivers/usb/dwc3/platform_data.h
+++ b/drivers/usb/dwc3/platform_data.h
@@ -24,6 +24,7 @@
 	enum usb_device_speed maximum_speed;
 	enum usb_dr_mode dr_mode;
 	bool tx_fifo_resize;
+	bool usb3_lpm_capable;
 
 	unsigned is_utmi_l1_suspend:1;
 	u8 hird_threshold;