haiku_loader: add memchr to the list of imported libroot objects

* libfdt uses memchr, so add this function from the libroot objects

(cherry picked from my sam460ex branch)

src/system/boot/Jamfile

@@ -6,6 +6,7 @@ local librootFunctions =
 	LocaleData.o
 	qsort.o
 	kernel_vsprintf.o
+	memchr.o
 	memcmp.o
 	memmove.o
 	strdup.o