Change microwatt from manual macro placement to mpl2

| Metric | Old | New | Type |
| ------ | --- | --- | ---- |
| finish__timing__drv__hold_violation_count | 750 | 200 | Tighten |

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

Author: maliberty

flow/designs/sky130hd/microwatt/config.mk

@@ -21,7 +21,9 @@ export ADDITIONAL_LEFS  = $(wildcard $(microwatt_DIR)/lef/*.lef)
 
 export ADDITIONAL_LIBS = $(wildcard $(microwatt_DIR)/lib/*.lib)
 
-export MACRO_PLACEMENT = $(microwatt_DIR)/microwatt.macro_placement.cfg
+export SYNTH_HIERARCHICAL = 1
+
+export RTLMP_FLOW = True
 
 # CTS tuning
 export CTS_BUF_CELL = sky130_fd_sc_hd__clkbuf_8