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/des.c b/library/des.c
index 9281747..7f90faa 100644
--- a/library/des.c
+++ b/library/des.c
@@ -400,8 +400,8 @@
     int i;
     uint32_t X, Y, T;
 
-    MBEDTLS_GET_UINT32_BE( X, key, 0 );
-    MBEDTLS_GET_UINT32_BE( Y, key, 4 );
+    X = MBEDTLS_GET_UINT32_BE( key, 0 );
+    Y = MBEDTLS_GET_UINT32_BE( key, 4 );
 
     /*
      * Permuted Choice 1
@@ -610,8 +610,8 @@
 
     SK = ctx->sk;
 
-    MBEDTLS_GET_UINT32_BE( X, input, 0 );
-    MBEDTLS_GET_UINT32_BE( Y, input, 4 );
+    X = MBEDTLS_GET_UINT32_BE( input, 0 );
+    Y = MBEDTLS_GET_UINT32_BE( input, 4 );
 
     DES_IP( X, Y );
 
@@ -697,8 +697,8 @@
 
     SK = ctx->sk;
 
-    MBEDTLS_GET_UINT32_BE( X, input, 0 );
-    MBEDTLS_GET_UINT32_BE( Y, input, 4 );
+    X = MBEDTLS_GET_UINT32_BE( input, 0 );
+    Y = MBEDTLS_GET_UINT32_BE( input, 4 );
 
     DES_IP( X, Y );