Add license header for Minio modifications, improvements for sha1,sha256,sha512 implementations

Also bring in SSE3 optimized public domain implementation of SHA1 from Intel ``FIPS PUB 180-1``

pkg/utils/crypto/sha1/sha1_amd64.S

@@ -59,14 +59,19 @@
  * SHA-1 implementation with Intel(R) AVX2 instruction set extensions.
  *
  *This implementation is based on the previous SSSE3 release:
- *Visit http://software.intel.com/en-us/articles/
- *and refer to improving-the-performance-of-the-secure-hash-algorithm-1/
+ * https://software.intel.com/en-us/articles/improving-the-performance-of-the-secure-hash-algorithm-1
  *
  *Updates 20-byte SHA-1 record in 'hash' for even number of
  *'num_blocks' consecutive 64-byte blocks
  *
  */
 
+/*
+ * Using this part of Minio codebase under the license
+ * Apache License Version 2.0 with modifications
+ *
+ */
+
 #ifdef HAS_AVX2
 #ifndef ENTRY
 #define ENTRY(name) \