msm_fb: display: reference count base pipe free in dsi and lcdc

During dsi off or lcdc off, base pipe could be freeed if fb device is
closed. Since base pipe allocation and free are managed through
reference counting api functions, so those free functions api should
be called.

Change-Id: I210716a590cde87ee254184a42d9df38c8012ff6
Signed-off-by: Huaibin Yang <huaibiny@codeaurora.org>