stm32mp1: correct plat_crash_console_flush()
stm32mp1: correct plat_crash_console_flush()

The base address of UART peripheral should be given in R0, not in R1.
Otherwise the console_stm32_core_flush issues an assert message.
This issue was highlighted with recent changes in console flush functions.

Change-Id: Iead01986fdbbf30ad2fd9fa515a1d2b611b4e591
Signed-off-by: Yann Gautier <e753f6969c288905606e3c07464886d4f1fc1be0@st.com>

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