Revert "Add pk_rsa_set_padding() and rsa_set_padding()"

This reverts commit b4fae579e8.

Conflicts:
	library/pk.c
	tests/suites/test_suite_pk.data
	tests/suites/test_suite_pk.function

library/rsa.c

@@ -60,17 +60,6 @@ void rsa_init( rsa_context *ctx,
 #endif
 }
 
-/*
- * Set padding method after initialisation
- */
-void rsa_set_padding( rsa_context *ctx,
-                      int padding,
-                      int hash_id)
-{
-    ctx->padding = padding;
-    ctx->hash_id = hash_id;
-}
-
 #if defined(POLARSSL_GENPRIME)
 
 /*