dt-bindings: usb: qcom,dwc3: Make ss_phy_irq optional for X1E80100

dt-bindings: usb: qcom,dwc3: Make ss_phy_irq optional for X1E80100

X1 has multiple DWC3 hosts, including one that's USB2, which naturally
means it doesn't have a SuperSpeed interrupt. Make it optional to fix
warnings such as:

usb@a2f8800: interrupt-names: ['pwr_event', 'dp_hs_phy_irq', 'dm_hs_phy_irq'] is too short

Signed-off-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://lore.kernel.org/r/20241116-topic-x1e_usb2_bindings-v1-1-dde2d63f428f@oss.qualcomm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>