adds RISCV-VP platform

env/riscv_vp/memory_map.ld

@@ -0,0 +1,7 @@
+MEMORY
+{
+  ram   (wxa!ri) : ORIGIN = 0x00000000, LENGTH = 128K
+  rom   (rxai!w) : ORIGIN = 0x1000E000, LENGTH = 2k
+  flash (rxai!w) : ORIGIN = 0x20000000, LENGTH = 16M
+  dram  (wxa!ri) : ORIGIN = 0x40000000, LENGTH = 2048M
+}