drm/tilcdc: Load palette at the end of mode_set_nofb()

Load palette at the end of mode_set_nofb(). Moving the palette loading
to mode_set_nofb() saves us from storing and restoring of framebuffer
addresses in dma registers that were just recently written there.

Signed-off-by: Jyri Sarha <jsarha@ti.com>
Tested-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>