target: msm8994: add support for 90 phase DSI PLL VCO frequency

Enable DSI PLL VCO phase configuration to have 90 phase
difference between dsi bit clock and dsi byte clock.

Change-Id: Ifdd36f93a5340ff9c612d4528f38bfdc252d0210
diff --git a/target/msm8994/rules.mk b/target/msm8994/rules.mk
index 3637a57..9c02201 100644
--- a/target/msm8994/rules.mk
+++ b/target/msm8994/rules.mk
@@ -16,6 +16,8 @@
 DEFINES += DISPLAY_TYPE_MIPI=1
 DEFINES += DISPLAY_TYPE_DSI6G=1
 
+DEFINES += DISPLAY_EN_20NM_PLL_90_PHASE
+
 MODULES += \
 	dev/keys \
 	dev/pmic/pm8x41 \