rm_work: adjust dependency to make do_rm_work_all depend on do_rm_work

For now, if we use rm_work and `bitbake core-image-minimal', some
recipes' WORKDIRs are not cleaned up, e.g., makedevs-native.

Adjust the dependency to make do_rm_work_all depend on do_rm_work
to solve this problem.

Below are the detailed explanation of why this would work.

Without this patch, the dependency chain is like:
[other deps] -> [do_rm_work] -+-> [do_build]
                              |
[do_rm_work_all] -------------+

With this patch, the depedency chain is like:
[other deps] -> [do_rm_work] -> [do_rm_work_all] -> [do_build]

Such dependency chain adjustment fixes the issue because do_rm_work_all
now depends on [other deps] and thus the [depends] of these [other deps].
Take core-image-minimal as an example. Before this adjustment,
do_rm_work_all does not have any relationship with do_rootfs, and we have
do_rootfs[depends] += "makedevs-native:do_populate_sysroot ..."
This essentially prevents 'recrdeptask' setting of do_rm_work_all extend
to makedevs-native. With this patch, the do_rm_work_all now depends
on do_rm_work which in turn depends on do_rootfs, and so do_rm_work_all's
recrdeptask could have effect on makedevs-native.

With this patch, all built recipes WORKDIR will be cleaned up with
a few expected exceptions such as kernel and qemu-helper-native.

Signed-off-by: Chen Qi <Qi.Chen@windriver.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>