[rdkb][common][app][Refactor wifi agent bbappend]

[Description]
1. add _PLATFORM_TURRIS_ into CFLAGS to make sure wifi agent can compatible hal-wifi-mt76

[Release-log]

Change-Id: I8cc6aabf26d8527c37b4ded255923c690d62a96e
diff --git a/recipes-wifi/ccsp/ccsp-wifi-agent.bbappend b/recipes-wifi/ccsp/ccsp-wifi-agent.bbappend
index f0b28ec..68ce82a 100644
--- a/recipes-wifi/ccsp/ccsp-wifi-agent.bbappend
+++ b/recipes-wifi/ccsp/ccsp-wifi-agent.bbappend
@@ -1,6 +1,6 @@
 FILESEXTRAPATHS_append := "${THISDIR}/files:"
 
-CFLAGS_append += " -DWIFI_HAL_VERSION_3 -DCONFIG_DFS -D_WIFI_AX_SUPPORT_ "
+CFLAGS_append += " -DWIFI_HAL_VERSION_3 -DCONFIG_DFS -D_WIFI_AX_SUPPORT_ -D_PLATFORM_TURRIS_ "
 
 SRC_URI_append += " \
     file://fix_guardInterval_set_issue.patch;apply=no \