package/igh-ethercat: remove stale patch 0002

igh-ethercat is failing while attempting to apply patches,
with error:

    Applying 0002-Linux-6.19.0-support.patch using patch:
    patching file devices/generic.c
    Reversed (or previously applied) patch detected!  Skipping patch.
    1 out of 1 hunk ignored -- saving rejects to file devices/generic.c.rej

The package patch 0002 was added in [1] in branch "master" while it
was in release client cycle. It was cherry-picked in [2] in branch
"next" to apply the bump [3] (which removes the package patches 0001
and 0002). When the branch "next" was merged in "master" in commit [4],
the patch 0002 was kept.

This commit removes this stale patch.

[1] https://gitlab.com/buildroot.org/buildroot/-/commit/e4cf512c394f218cc71eb6b496ce4cb004c917bb
[2] https://gitlab.com/buildroot.org/buildroot/-/commit/8a5fc970b48a432f5df3be1f1e7667095e712b3d
[3] https://gitlab.com/buildroot.org/buildroot/-/commit/0a91e760f467a90b0f0acf00ec76aac011b241f1
[4] https://gitlab.com/buildroot.org/buildroot/-/commit/5f2687795595c9af579312c1d504373ece56f43f

Fixes:
- https://autobuild.buildroot.org/results/4f509f1f788c1b8dc5a840ffa2e435c5ed7b6eea/

Signed-off-by: Julien Olivain <ju.o@free.fr>
(cherry picked from commit d0718179694b407cb93f1603cdf845997dac7345)
Signed-off-by: Raphaël Mélotte <raphael.melotte@mind.be>