[OE-core] krogoth's core-image-minimal is much bigger than jethro's

[Robert Yang]

* For ext4:
   11M -> 26M
   The similar to vmdk, qcow2 and iso.

* For tar.bz2:
   2.7M -> 4.5M

The main problem is eudev-hwdb which would be 12M after installed, jethro
doesn't use this, but udev by default, and it's gone in krogoth.
$ du -sh core-image-minimal/1.0-r0/rootfs/etc/udev/*
0        core-image-minimal/1.0-r0/rootfs/etc/udev/cache.data
6.4M     core-image-minimal/1.0-r0/rootfs/etc/udev/hwdb.bin
5.2M     core-image-minimal/1.0-r0/rootfs/etc/udev/hwdb.d
8.0K     core-image-minimal/1.0-r0/rootfs/etc/udev/rules.d
4.0K     core-image-minimal/1.0-r0/rootfs/etc/udev/udev.conf

Is there an easier way to fix this problem, please ? It's not a good
news for the user who uses core-imag-minimal/udev when they want to
upgrade to krogoth. And this would hurt the small device which uses
udev.


The conf is:
MACHINE = "qemux86-64"
DISTRO = "poky"
PACKAGE_CLASSES = "package_rpm"
EXTRA_IMAGE_FEATURES = "debug-tweaks"
USER_CLASSES = "buildstats image-mklibs"

$ bitbake core-image-minimal

For jethro:
$ ls -lh core-image-minimal-qemux86-64-20160513061306.rootfs.ext4
11M  core-image-minimal-qemux86-64-20160513061306.rootfs.ext4
$ du -sh core-image-minimal-qemux86-64-20160513061306.rootfs.ext4
7.9M core-image-minimal-qemux86-64-20160513061306.rootfs.ext4

For krogoth:

$ ls -lh core-image-minimal-qemux86-64-20160513061459.rootfs.ext4
26M core-image-minimal-qemux86-64-20160513061459.rootfs.ext4

$ du -sh core-image-minimal-qemux86-64-20160513061459.rootfs.ext4
core-image-minimal-qemux86-64-20160513061459.rootfs.ext4

-- 
Thanks

Robert