ARM add initial support for the Phytium Pe2201 Board.

Add pe2201 platform code and the device tree of pe2201 platform board.
The initial support comprises the UART and PCIe.

Signed-off-by: TracyMg_Li <TracyMg_Li@outlook.com>
Changes since v1:
        fix space corrupt.
Changes since v2:
        switch to bootstd and text environment.
Changes since v3:
        add environment variables.
diff --git a/arch/arm/dts/Makefile b/arch/arm/dts/Makefile
index 640442a..89c2986 100644
--- a/arch/arm/dts/Makefile
+++ b/arch/arm/dts/Makefile
@@ -1480,6 +1480,7 @@
 
 dtb-$(CONFIG_TARGET_DURIAN) += phytium-durian.dtb
 dtb-$(CONFIG_TARGET_POMELO) += phytium-pomelo.dtb
+dtb-$(CONFIG_TARGET_PE2201) += phytium-pe2201.dtb
 
 dtb-$(CONFIG_TARGET_PRESIDIO_ASIC) += ca-presidio-engboard.dtb