Merge changes from topic "fix_sparse_warnings" into integration

* changes:
  fix(libc): remove __putchar alias
  fix(console): correct scopes for console symbols
  fix(auth): use NULL instead of 0 for pointer check
  fix(io): compare function pointers with NULL
  fix(fdt-wrappers): use correct prototypes

diff --cc drivers/auth/mbedtls/mbedtls_x509_parser.c
Simple merge