[slave.mk]: Move initialization of ENABLE_SYNCD_RPC up (#680)

ENABLE_SYNCD_RPC should be initialized before all recipes are included
in order for them to be able to use this variable

Signed-off-by: marian-pritsak <marianp@mellanox.com>

slave.mk

@@ -51,6 +51,9 @@ distclean : .platform clean
 ## Include other rules
 ###############################################################################
 
+ifeq ($(SONIC_ENABLE_SYNCD_RPC),y)
+ENABLE_SYNCD_RPC = y
+endif
 
 include $(RULES_PATH)/config
 include $(RULES_PATH)/functions
@@ -67,10 +70,6 @@ ifeq ($(PASSWORD),)
 override PASSWORD := $(DEFAULT_PASSWORD)
 endif
 
-ifeq ($(SONIC_ENABLE_SYNCD_RPC),y)
-ENABLE_SYNCD_RPC = y
-endif
-
 MAKEFLAGS += -j $(SONIC_CONFIG_BUILD_JOBS)
 
 ###############################################################################