qcacld-3.0: Add flag for protected dp peer access

Add compiler preprocessor directive to enable DP peer
protected access mechanism in Kbuild for lithium dp.

Change-Id: I3808369b4c0ef678d448b7536fd29dee8748e9ba
CRs-Fixed: 2309393
diff --git a/Kbuild b/Kbuild
index 62009c7..4447cb9 100644
--- a/Kbuild
+++ b/Kbuild
@@ -2230,6 +2230,7 @@
 cppflags-$(CONFIG_WLAN_FEATURE_11AX) += -DSUPPORT_11AX_D3
 
 cppflags-$(CONFIG_LITHIUM) += -DFEATURE_AST
+cppflags-$(CONFIG_LITHIUM) += -DPEER_PROTECTED_ACCESS
 
 # Vendor Commands
 cppflags-$(CONFIG_FEATURE_RSSI_MONITOR) += -DFEATURE_RSSI_MONITOR