configs: stm32mp1: enable the fastboot oem command bootbus
Enable the fastboot oem command bootbus, used to configure the eMMC
boot behavior, with same format than 'mmc bootbus'
and with parameter: boot_bus_width reset_boot_bus_width boot_mode
On stm32mp1 boards the expected command is
$> fastboot oem partconf:0 0 0
Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>
Reviewed-by: Patrice Chotard <patrice.chotard@st.com>