drm/msm: move irq utils to mdp_kms

We'll want basically the same thing for mdp5, so refactor it out so it
can be shared.

Signed-off-by: Rob Clark <robdclark@gmail.com>
diff --git a/drivers/gpu/drm/msm/Makefile b/drivers/gpu/drm/msm/Makefile
index 9481736..17847af 100644
--- a/drivers/gpu/drm/msm/Makefile
+++ b/drivers/gpu/drm/msm/Makefile
@@ -13,6 +13,7 @@
 	hdmi/hdmi_phy_8960.o \
 	hdmi/hdmi_phy_8x60.o \
 	mdp/mdp_format.o \
+	mdp/mdp_kms.o \
 	mdp/mdp4/mdp4_crtc.o \
 	mdp/mdp4/mdp4_dtv_encoder.o \
 	mdp/mdp4/mdp4_irq.o \