config: Update script to set cache line size on system

This patch changes the config scripts such that they do not set the
cache line size per cache instance, but rather for the system as a
whole.

configs/splash2/run.py

@@ -160,7 +160,6 @@ class Water_spatial(LiveProcess):
 
 class L1(BaseCache):
     latency = options.l1latency
-    block_size = 64
     mshrs = 12
     tgts_per_mshr = 8
 
@@ -169,7 +168,6 @@ class L1(BaseCache):
 # ----------------------
 
 class L2(BaseCache):
-    block_size = 64
     latency = options.l2latency
     mshrs = 92
     tgts_per_mshr = 16