fix: override PDN_TCL for riscv32i-mock-sram to fix PDN-0232/0233

The platform default BLOCKS_grid_strategy.tcl produces empty PDN
grids. Use BLOCK_grid_strategy.tcl which has M4-M5 connections
matching the block's MAX_ROUTING_LAYER=M4 constraint.

Cherry-pick of PR #4091.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Signed-off-by: Øyvind Harboe <oyvind.harboe@zylin.com>

Author: oharboe

flow/designs/asap7/riscv32i-mock-sram/config.mk

@@ -1,5 +1,11 @@
 export DESIGN_NICKNAME = riscv32i-mock-sram
 export BLOCKS=fakeram7_256x32
 
+# Override platform default (BLOCKS_grid_strategy.tcl) which defines an
+# ElementGrid macro grid with no stripes, producing empty PDN grids
+# (PDN-0232/0233). BLOCK_grid_strategy.tcl uses M4-M5 connections that
+# match the block's MAX_ROUTING_LAYER=M4 constraint.
+export PDN_TCL = $(PLATFORM_DIR)/openRoad/pdn/BLOCK_grid_strategy.tcl
+
 include designs/asap7/riscv32i/config.mk