drm/amd/display: Whitespace cleanup

Commit 075e2099c32c ("drm/amd/display: Fix race condition in DPIA AUX
transfer") was backported to stable, which I noticed because of git
saying

	linux-6.1/.git/rebase-apply/patch:37154: space before tab in indent.

while applying patch-6.1.21. While fixing the code location that issued
that warning, improve in few more places.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Hamza Mahfooz <hamza.mahfooz@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>