fix(plat/st): panic if boot interface is wrong
fix(plat/st): panic if boot interface is wrong

Add a panic() at the end of stm32mp_io_setup() if the boot interface
given in ROM code boot context is not supported.

Change-Id: I0d50f21a11231febd21041b6e63108cc3e6f4f0c
Signed-off-by: Yann Gautier <e753f6969c288905606e3c07464886d4f1fc1be0@foss.st.com>

achingupta/arm-trusted-firmware,achingupta/arm-trusted-firmware