Revert "kernel.bbclass: adjust a condition checking"

Revert "kernel.bbclass: adjust a condition checking"

This reverts commit 6676411fccff2d331878e4ca1f9411aafb056a80.

This revert restores the original code and adds a comment.  The commit
that was reverted broke a number of wic templates and tools which rely
on the initramfs creation dependency and the case where the
INITRAMFS_IMAGE_BUNDLE is not set.

If an end user does not want the INITRAMFS_IMAGE generated, it should
be set to "".

[ Issue: LIN1019-1791 ]

(From OE-Core rev: ab61a11623ac0a25ba1c98d686c79815abab573f)

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>