Even though at this point plat_crash_console_flush is optional, it will
stop being optional in a following patch.

The console driver of warp7 doesn't support flush, so the implementation
is a placeholder.

TI had ``plat_crash_console_init`` and ``plat_crash_console_putc``, but
they weren't global so they weren't actually used. Also, they were
calling the wrong functions.

imx8_helpers.S only has placeholders for all of the functions.

Change-Id: I8d17bbf37c7dad74e134c61ceb92acb9af497718
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

This patch adds a callback into the BootROM's provided High Assurance Boot
(HAB) failsafe function when panicking i.e. the call is done without making
use of stack.

The HAB failsafe function allows a piece of software to call into the
BootROM and place the processor into failsafe mode.

Failsafe mode is a special mode which presents a serial download protocol
interface over UART or USB at the time of writing.

If the board has been set into secure mode, then only a signed binary can
be used to recover the board.

Thus failsafe gives a putatively secure method of performing a secure
recovery over UART or USB.

Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Reviewed-by: Ryan Harkin <ryan.harkin@linaro.org>

This commit adds a warp7_helpers.S which contains a implementation of:

- platform_mem_init
- plat_get_my_entrypoint
- plat_crash_console_init
- plat_crash_console_putc

Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>