plat: imx8mm: Add initial defintions to facilitate FIP layout

Adds a number of definitions consistent with the established WaRP7
equivalents specifying number of io_handles and block devices.

Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Signed-off-by: Ying-Chun Liu (PaulLiu) <paulliu@debian.org>
Change-Id: If1d7ef1ad3ac3dfc860f949392c7534ce8d206e3
1 file changed