add numerical recipes library

lib/nr/ansi/recipes/icrc1.c

@@ -0,0 +1,14 @@
+
+unsigned short icrc1(unsigned short crc, unsigned char onech)
+{
+	int i;
+	unsigned short ans=(crc ^ onech << 8);
+
+	for (i=0;i<8;i++) {
+		if (ans & 0x8000)
+			ans = (ans <<= 1) ^ 4129;
+		else
+			ans <<= 1;
+	}
+	return ans;
+}