drm/ssd130x: ensure ssd132x pitch is correct

drm/ssd130x: ensure ssd132x pitch is correct

The bounding rectangle is adjusted to ensure it aligns to
SSD132X_SEGMENT_WIDTH, which may adjust the pitch.  Calculate the pitch
after aligning the left and right edge.

Fixes: fdd591e00a9c ("drm/ssd130x: Add support for the SSD132x OLED controller family")
Signed-off-by: John Keeping <jkeeping@inmusicbrands.com>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250115110139.1672488-3-jkeeping@inmusicbrands.com
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>