sysclk: make dvfs work

Source/sys-clk/common/src/memmem.c

@@ -0,0 +1,59 @@
+#include "memmem.h"
+
+void *memmem_impl(void *haystack, size_t haystacklen, const void *needle, size_t needlelen)
+{
+	const unsigned char *cmpp;
+	const unsigned char *p;
+	const unsigned char *endp;
+	const unsigned char *q;
+	const unsigned char *endq;
+	unsigned char found;
+
+	if(haystack == NULL)
+	{
+		return NULL;
+	}
+	if(needle == NULL)
+	{
+		return haystack;
+	}
+	if(haystacklen == 0)
+	{
+		return NULL;
+	}
+	if(needlelen == 0)
+	{
+		return haystack;
+	}
+
+	if(needlelen > haystacklen)
+	{
+		return NULL;
+	}
+
+	endp = haystack + haystacklen - needlelen;
+	endq = needle + needlelen;
+	for(p = haystack; p <= endp; p++)
+	{
+		found = 1;
+		cmpp = p;
+		for(q = needle; q < endq; q++)
+		{
+			if(*cmpp != *q)
+			{
+				found = 0;
+				break;
+			}
+			else
+			{
+				cmpp++;
+			}
+		}
+		if(found)
+		{
+			return (void*)p;
+		}
+	}
+
+  return NULL;
+}