Add support of stm32mp157c-ev1, the evaluation board with pmic stpmu1
(ev1 = mother board + daughter ed1) with device tree.
EV1 is the selected board by default in basic defconfig.
PS: CONFIG_PINCTRL_FULL activation avoid to increase
SYS_MALLOC_F_LEN (Early malloc usage: 2034)
Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>