rockchip/rk3399: enable PMU_PERILP_PD_EN bit when suspend

rockchip/rk3399: enable PMU_PERILP_PD_EN bit when suspend

with PMU_PERILP_PD_EN bit enable, the soc will shutdown
cm0, crypto, dcf, imem(normal SRAM), dmac, bootrom, efuse_con,
spi, i2c, uart, saradc, tsadc when suspend, we have M0 code
need to run when suspend in normal SRAM, so we need to take
care of that.

Change-Id: I8c066637e5b81d4b1d53197450b9d592cbe00793
Signed-off-by: Lin Huang <hl@rock-chips.com>
Signed-off-by: Derek Basehore <dbasehore@chromium.org>
Signed-off-by: Caesar Wang <wxt@rock-chips.com>