Revert "drm/amd/amdgpu: add pipe1 hardware support"

This reverts commit 4c763180.

Triggered GFX hangs with GNOME Wayland on Navi 21.

Bug: https://gitlab.freedesktop.org/drm/amd/-/issues/2117


Signed-off-by: Michel Dänzer <mdaenzer@redhat.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>