Reduce MACRO_PLACE_HALO in asap7/aes-block to 5

The blocks are artificially small and the default halos is too
large.

Signed-off-by: Matt Liberty <[email protected]>

Author: maliberty

flow/designs/asap7/aes-block/config.mk

@@ -25,4 +25,7 @@ export MAX_ROUTING_LAYER      = M9
 
 # Ignore power at this exploratory level
 export GND_NETS_VOLTAGES      = ""
-export PWR_NETS_VOLTAGES      = ""
+export PWR_NETS_VOLTAGES      = ""
+
+# The macros are very small so use a smaller halo
+export MACRO_PLACE_HALO        ?= 5 5