riscv: nx25: include: Add header files to support RISC-V

Add header files for RISC-V.
Cache, ptregs, data type and other definitions are included.

Signed-off-by: Rick Chen <rick@andestech.com>
Signed-off-by: Rick Chen <rickchen36@gmail.com>
Signed-off-by: Greentime Hu <green.hu@gmail.com>
diff --git a/arch/riscv/include/asm/unaligned.h b/arch/riscv/include/asm/unaligned.h
new file mode 100644
index 0000000..6cecbbb
--- /dev/null
+++ b/arch/riscv/include/asm/unaligned.h
@@ -0,0 +1 @@
+#include <asm-generic/unaligned.h>