plat: imx8mp: Add the basic support for i.MX8MP

The i.MX 8MP Media Applications Processor is part of the growing
i.MX8M family targeting the consumer and industrial market. It brings
an effective Machine Learning and AI accelerator that enables a new
class of applications. It is built in 14LPP to achieve both high
performance and low power consumption and relies on a powerful fully
coherent core complex based on a quad core Arm Cortex-A53 cluster and
Cortex-M7 low-power coprocessor, audio digital signal processor, machine
learning and graphics accelerators.

Signed-off-by: Jacky Bai <ping.bai@nxp.com>
Change-Id: I98311ebc32bee20af05031492e9fc24d06e55f4a
diff --git a/docs/plat/imx8m.rst b/docs/plat/imx8m.rst
index ba087a2..f184b69 100644
--- a/docs/plat/imx8m.rst
+++ b/docs/plat/imx8m.rst
@@ -33,6 +33,7 @@
    Target_SoC should be "imx8mq" for i.MX8MQ SoC.
    Target_SoC should be "imx8mm" for i.MX8MM SoC.
    Target_SoC should be "imx8mn" for i.MX8MN SoC.
+   Target_SoC should be "imx8mp" for i.MX8MP SoC.
 
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