libxml-parser-perl-native: Remove uneeded entries:

libxml-parser-perl-native: Remove uneeded entries:
* DEPENDS on perl-native isn't needed since cpan.bbclass adds this.
* DEPENDS on expat-native isn't needed since libxml-parser-perl adds this.
* RDEPENDS on perl-native was only here to prevent an RDEPENDS on perl. The
  RDEPENDS was being added by cpan.bbclass, but that has now been fixed to
  not add it for native packages. This needed to be removed so that perl
  isn't built when you only want libxml-parser-perl-native.