image.bbclass: drop initramfs bundle related code

image.bbclass: drop initramfs bundle related code

The original purpose of this code snippet was to repackage initramfs
bundled kernel images before do_image_complete, to be able to be
included by rootfs, but it's not going to achieve that since the
initramfs bundled kernel images are not even installed to ${D}/boot
after commit a49569e3a7534779bbe3f01a0647fd076c95798d:
[ kernel.bbclass: do not copy bundled initramfs to /boot ]

So there is not a initramfs bundled kernel package at all, we should
drop the code, because it is leading kernel do_initramfs_bundle
unnecessarily rerun and it's very time consuming and hence is impacting
the performance a lot.

(From OE-Core rev: eca501aeb4f2cc9255fabab14c68f6910367aaf9)

Signed-off-by: Ming Liu <peter.x.liu@external.atlascopco.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>