drm/rockchip: add an common abstracted PSR driver

The PSR driver have exported four symbols for specific device driver, and
it's safe to call them in interrupt context:
- rockchip_drm_psr_register()
- rockchip_drm_psr_unregister()
- rockchip_drm_psr_enable()
- rockchip_drm_psr_disable()
- rockchip_drm_psr_flush()

Encoder driver should call the register/unregister interfaces to hook
itself into common PSR driver, encoder have implement the 'psr_set'
callback which use the set PSR state in hardware side.

Crtc driver would call the enable/disable interfaces when vblank is
enable/disable, after that the common PSR driver would call the encoder
registered callback to set the PSR state.

Fb driver would call the flush interface in 'fb->dirty' callback, this
helper function would force all PSR enabled encoders to exit from PSR
for 3 seconds.

Signed-off-by: Yakir Yang <ykk@rock-chips.com>
[seanpaul removed leftover psr_enabled/psr_work kruft from drm_vop.c]
Signed-off-by: Sean Paul <seanpaul@chromium.org>
diff --git a/drivers/gpu/drm/rockchip/Makefile b/drivers/gpu/drm/rockchip/Makefile
index 05d0713..9746365 100644
--- a/drivers/gpu/drm/rockchip/Makefile
+++ b/drivers/gpu/drm/rockchip/Makefile
@@ -3,7 +3,7 @@
 # Direct Rendering Infrastructure (DRI) in XFree86 4.1.0 and higher.
 
 rockchipdrm-y := rockchip_drm_drv.o rockchip_drm_fb.o \
-		rockchip_drm_gem.o rockchip_drm_vop.o
+		rockchip_drm_gem.o rockchip_drm_psr.o rockchip_drm_vop.o
 rockchipdrm-$(CONFIG_DRM_FBDEV_EMULATION) += rockchip_drm_fbdev.o
 
 obj-$(CONFIG_ROCKCHIP_ANALOGIX_DP) += analogix_dp-rockchip.o