LMS: initial implementation

Initial wolfSSL implementation of LMS.
Changed LMS benchmarking to time making a key and reloading.
SHA-256:
  Added wc_Sha256HashBlock to make hashing a block fast.
Fixed assembly code to be able to hash a block from an external
buffer.
  Simplified code were possible.
Moved byte reversal decision logic to one place instead of replicating
length checks.

Author: SparkiDev

configure.ac

@@ -1289,6 +1289,10 @@ do
     LMS_VERIFY_ONLY=yes
     AM_CFLAGS="$AM_CFLAGS -DWOLFSSL_LMS_VERIFY_ONLY"
     ;;
+  small)
+    ENABLED_WC_LMS=yes
+    AM_CFLAGS="$AM_CFLAGS -DWOLFSSL_WC_LMS_SMALL"
+    ;;
   wolfssl)
     ENABLED_WC_LMS=yes
     AM_CFLAGS="$AM_CFLAGS -DWOLFSSL_WC_LMS"

src/include.am

@@ -710,6 +710,7 @@ endif
 
 if BUILD_WC_LMS
 src_libwolfssl@LIBSUFFIX@_la_SOURCES += wolfcrypt/src/wc_lms.c
+src_libwolfssl@LIBSUFFIX@_la_SOURCES += wolfcrypt/src/wc_lms_impl.c
 endif
 
 if BUILD_WC_XMSS