adds riscv_vp platform

platform/riscv_vp/Kconfig

@@ -0,0 +1,16 @@
+# SPDX-License-Identifier: BSD-2-Clause
+
+#
+# All mandatory drivers or libraries for this platform should
+# be directly selected by the PLATFORM_xyz kconfig symbol.
+#
+# All optional drivers or libraries for this platform should
+# be enabled via configs/defconfig of this platform.
+#
+config PLATFORM_TEMPLATE
+	bool
+	select IPI_MSWI
+	select IRQCHIP_PLIC
+	select SERIAL_UART8250
+	select TIMER_MTIMER
+	default n