design: Enable Kepler formal for gf12/bp_quad

Signed-off-by: Jaehyun Kim <jhkim@precisioninno.com>

Author: jhkim-pii

flow/designs/gf12/bp_quad/config.mk

@@ -68,5 +68,3 @@ export MACRO_WRAPPERS = $(PLATFORM_DIR)/bp/wrappers/wrappers.tcl
 export PDN_TCL = $(PLATFORM_DIR)/cfg/pdn_grid_strategy_13m_9T.top.tcl
 
 export MACRO_PLACE_HALO = 7 7
-
-export LEC_CHECK = 0