ARM: dts: stm32: Connect PHY IRQ line on DH STM32MP1 SoM

ARM: dts: stm32: Connect PHY IRQ line on DH STM32MP1 SoM

On the production DHCOM STM32MP15xx SoM, the PHY IRQ line is connected
to the PI11 pin. Describe it in the DT as well, so the PHY IRQ can be
used e.g. to detect cable insertion and removal.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Alexandre Torgue <alexandre.torgue@st.com>
Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
Cc: Patrice Chotard <patrice.chotard@st.com>
Cc: Patrick Delaunay <patrick.delaunay@st.com>
Cc: linux-stm32@st-md-mailman.stormreply.com
To: linux-arm-kernel@lists.infradead.org
Signed-off-by: Alexandre Torgue <alexandre.torgue@st.com>