ide: split away ide-pci.c

create ide-pci.c and place pci bus support there.
only build ide-pci support for platforms using it.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

Fix build (merge with isa mmio split)
diff --git a/hw/ppc_newworld.c b/hw/ppc_newworld.c
index 35a9858..3ad0057 100644
--- a/hw/ppc_newworld.c
+++ b/hw/ppc_newworld.c
@@ -35,6 +35,7 @@
 #include "fw_cfg.h"
 #include "escc.h"
 #include "openpic.h"
+#include "ide.h"
 
 #define MAX_IDE_BUS 2
 #define VGA_BIOS_SIZE 65536