[MIPS] JAZZ fixes

- restructured irq handling
- switched vdma to use memory allocated via get_free_pages
- setup platform devices for serial, jazz_esp and jazzsonic
- fixed cmos rtc access

Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>