asn1: enable mbedtls_asn1_get_tag() when PEM_PARSE_C is defined

Signed-off-by: Valerio Setti <valerio.setti@nordicsemi.no>
diff --git a/library/asn1parse.c b/library/asn1parse.c
index e33fdf7..644b43b 100644
--- a/library/asn1parse.c
+++ b/library/asn1parse.c
@@ -8,7 +8,7 @@
 #include "common.h"
 
 #if defined(MBEDTLS_ASN1_PARSE_C) || defined(MBEDTLS_X509_CREATE_C) || \
-    defined(MBEDTLS_PSA_UTIL_HAVE_ECDSA)
+    defined(MBEDTLS_PSA_UTIL_HAVE_ECDSA) || defined(MBEDTLS_PEM_PARSE_C)
 
 #include "mbedtls/asn1.h"
 #include "mbedtls/platform_util.h"
@@ -74,7 +74,8 @@
 
     return mbedtls_asn1_get_len(p, end, len);
 }
-#endif /* MBEDTLS_ASN1_PARSE_C || MBEDTLS_X509_CREATE_C || MBEDTLS_PSA_UTIL_HAVE_ECDSA */
+#endif /* MBEDTLS_ASN1_PARSE_C || MBEDTLS_X509_CREATE_C ||
+          MBEDTLS_PSA_UTIL_HAVE_ECDSA || MBEDTLS_PEM_PARSE_C */
 
 #if defined(MBEDTLS_ASN1_PARSE_C)
 int mbedtls_asn1_get_bool(unsigned char **p,