video/rk_eink: add poweren for tps65185

Signed-off-by: Weixin Zhou <zwx@rock-chips.com>
Change-Id: Icc6059a723f9e5d0b90c623497f0b03adea9e726

video/rk_eink: add rockchip eink support.

Signed-off-by: Wenping Zhang <wenping.zhang@rock-chips.com>
Change-Id: I39e92ee00690ea1be274b1abd94d54284ef36898