drm/radeon: Update pitch for page flip

When primary bo is updated, crtc's pitch may
have not been updated, this will lead to show
disorder content when user changes display mode,
we update crtc's pitch in page flip to avoid
this bug.
This refers to amdgpu's pageflip.

v1->v2:
Update all of the pitch in all of the page_flip functions
in radeon rather than just the evergreen one.

v2->v3:
Update pitch set method for r100 according to
radeon_legacy_crtc.c

Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: "Christian König" <christian.koenig@amd.com>
Cc: "Pan, Xinhui" <Xinhui.Pan@amd.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: amd-gfx@lists.freedesktop.org
Cc: dri-devel@lists.freedesktop.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Zhenneng Li <lizhenneng@kylinos.cn>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>