nios2: Build infrastructure

This patch adds Makefile and Kconfig files required for building a
nios2 kernel.

Signed-off-by: Ley Foon Tan <lftan@altera.com>
diff --git a/arch/nios2/lib/Makefile b/arch/nios2/lib/Makefile
new file mode 100644
index 0000000..5572566
--- /dev/null
+++ b/arch/nios2/lib/Makefile
@@ -0,0 +1,8 @@
+#
+# Makefile for Nios2-specific library files.
+#
+
+lib-y += delay.o
+lib-y += memcpy.o
+lib-y += memmove.o
+lib-y += memset.o