.mailmap: add entry for Leonard Göhrs

My very first kernel commit:

  e4e1d47c ("ALSA: ppc: remove redundant checks in PS3 driver probe")

was sent with the umlaut in my last name transcribed (Göhrs -> Goehrs).

Add a mailmap entry so all my commits use the same name.

Link: https://lkml.kernel.org/r/20230321145525.1317230-1-l.goehrs@pengutronix.de


Signed-off-by: Leonard Göhrs <l.goehrs@pengutronix.de>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>