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>
diff --git a/plat/rockchip/rk3368/drivers/pmu/pmu.c b/plat/rockchip/rk3368/drivers/pmu/pmu.c
index ad0b5ff..1767967 100644
--- a/plat/rockchip/rk3368/drivers/pmu/pmu.c
+++ b/plat/rockchip/rk3368/drivers/pmu/pmu.c
@@ -280,6 +280,16 @@
 	}
 }
 
+void sram_save(void)
+{
+	/* TODO: support the sdram save for rk3368 SoCs*/
+}
+
+void sram_restore(void)
+{
+	/* TODO: support the sdram restore for rk3368 SoCs */
+}
+
 int rockchip_soc_cores_pwr_dm_on(unsigned long mpidr, uint64_t entrypoint)
 {
 	uint32_t cpu, cluster;