ARM: dts: stm32: Add alternate pinmux for SDMMC pins on stm32mp15

ARM: dts: stm32: Add alternate pinmux for SDMMC pins on stm32mp15

Add another mux option for SDMMC1_D123DIR direction pins, SDMMC2 pins 4..7,
and SDMMC3 pins PD5_SDMMC3_D2 and PD0_SDMMC3_CMD, this is used on AV96 board.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Alexandre Torgue <alexandre.torgue@st.com>
Cc: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
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>