Revert "New function mbedtls_rsa_get_bitlen"

This reverts commit 1d26709dbd4a4f8ef9ea0ff58f2644a4bc3fc49c.
diff --git a/library/rsa.c b/library/rsa.c
index 499d145..56490f9 100644
--- a/library/rsa.c
+++ b/library/rsa.c
@@ -480,19 +480,12 @@
 /*
  * Get length in bytes of RSA modulus
  */
+
 size_t mbedtls_rsa_get_len( const mbedtls_rsa_context *ctx )
 {
     return( ctx->len );
 }
 
-/*
- * Get length in bits of RSA modulus
- */
-size_t mbedtls_rsa_get_bitlen( const mbedtls_rsa_context *ctx )
-{
-    return( mbedtls_mpi_bitlen( &ctx->N ) );
-}
-
 
 #if defined(MBEDTLS_GENPRIME)