GET macros use a target variable

The GET macros used to write to a macro parameter, but now
they can be used to assign a value to the desired variable
rather than pass it in as an argument and have it modified
in the macro function.

Due to this MBEDTLS_BYTES_TO_U32_LE is the same as
MBEDTLS_GET_UINT32_LE and was there for replaced in the
appropriate files and removed from common.h

Signed-off-by: Joe Subbiani <joe.subbiani@arm.com>
diff --git a/library/sha256.c b/library/sha256.c
index fb66340..c3573f8 100644
--- a/library/sha256.c
+++ b/library/sha256.c
@@ -190,7 +190,7 @@
     for( i = 0; i < 64; i++ )
     {
         if( i < 16 )
-            MBEDTLS_GET_UINT32_BE( local.W[i], data, 4 * i );
+            local.W[i] = MBEDTLS_GET_UINT32_BE( data, 4 * i );
         else
             R( i );
 
@@ -205,7 +205,7 @@
     }
 #else /* MBEDTLS_SHA256_SMALLER */
     for( i = 0; i < 16; i++ )
-        MBEDTLS_GET_UINT32_BE( local.W[i], data, 4 * i );
+        local.W[i] = MBEDTLS_GET_UINT32_BE( data, 4 * i );
 
     for( i = 0; i < 16; i += 8 )
     {