doc: dt: bindings: usb: dwc3: Update entries for disabling U1 and U2

This patch updates the documentation with the information related
to the quirks that needs to be added for disabling the link entering
into the U1 and U2 states
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Anurag Kumar Vulisha <anurag.kumar.vulisha@xilinx.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

Documentation/devicetree/bindings/usb/dwc3.txt

@@ -64,6 +64,8 @@ Optional properties:
  - snps,dis_u2_susphy_quirk: when set core will disable USB2 suspend phy.
  - snps,dis_enblslpm_quirk: when set clears the enblslpm in GUSB2PHYCFG,
 			disabling the suspend signal to the PHY.
+ - snps,dis-u1-entry-quirk: set if link entering into U1 needs to be disabled.
+ - snps,dis-u2-entry-quirk: set if link entering into U2 needs to be disabled.
  - snps,dis_rxdet_inp3_quirk: when set core will disable receiver detection
 			in PHY P3 power state.
  - snps,dis-u2-freeclk-exists-quirk: when set, clear the u2_freeclk_exists