Flush the FIFO before switching to runtime. This is so that there are
no lingering chars in the FIFO when we move to the runtime console.
TF-A plans to refactor the console_Switch_state(CONSOLE_FLAG_RUNTIME)
and console_flush() calls and make them the last calls in bl31_main()
(before BL31 exits). Until then they are being left as the last calls
in bl31_plat_runtime_setup() for testing before refactoring.
This patch affects the Mediatek platform only.
Change-Id: I83beee28ed856bc9b2f3131aa577be9bfa529028
Signed-off-by: Salman Nabi <salman.nabi@arm.com>