drm/panel: boe-tv101wum-ll2: Fix compilation build

drm/panel: boe-tv101wum-ll2: Fix compilation build

Commit 5d2b55e55e61 ("panel/boe-tv101wum-ll2: Use refcounted allocation
in place of devm_kzalloc()") switched from a kmalloc + drm_panel_init
call to a devm_drm_panel_alloc one.

However, the variable it was storing the allocated pointer in doesn't
exist, resulting in a compilation breakage.

Fixes: 5d2b55e55e61 ("panel/boe-tv101wum-ll2: Use refcounted allocation in place of devm_kzalloc()")
Signed-off-by: Maxime Ripard <mripard@kernel.org>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Tested-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://lore.kernel.org/r/20250408122008.1676235-3-mripard@kernel.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>