[POWERPC] Update arch/powerpc/boot/.gitignore

* Add dtbImage.*
* Added zImage.holly
* Folded zImage.coff.lds into zImage.*lds
* Removed some unused zImage.<foo> ignores

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

arch/powerpc/boot/.gitignore

@@ -20,21 +20,19 @@ kernel-vmlinux.strip.gz
 mktree
 uImage
 cuImage.*
+dtbImage.*
 treeImage.*
 zImage
+zImage.initrd
 zImage.bin.*
 zImage.chrp
 zImage.coff
-zImage.coff.lds
-zImage.ep*
+zImage.holly
 zImage.iseries
 zImage.*lds
 zImage.miboot
 zImage.pmac
 zImage.pseries
-zImage.redboot*
-zImage.sandpoint
-zImage.vmode
 zconf.h
 zlib.h
 zutil.h