uboot-phytec

ARM: dts: Add STMFX gpio expander support for stm32mp157c-ev1

Adds alias to set the pincontrol seq id.
For STMFX gpio expander, force sequence number after
the last bank (GPIOZ) to avoid conflict between STM32MP and STMFX
gpio bank sequence number.

Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>
Signed-off-by: Patrice Chotard <patrice.chotard@st.com>