docbook-sgml-dtd-native: converted to new style staging
* Converted do_stage to do_install.
* Moved the catalog files from ${sysconfdir}/sgml to ${D}${sysconfdir}/sgml so that they get included in the package file resulting with the new style staging.
* Added a function docbook_sgml_dtd_native_mangle, to correct the path in .cat file and added it to SYSROOT_PREPROCESS_FUNCS.
* Added INC_PR = "r1" to the .inc file and PR = "${INC_PR}.0" to the .bb files
Signed-off-by: Fahad Usman <fahad_usman@mentor.com>
Signed-off-by: Tom Rini <tom_rini@mentor.com>