Generate and use SCR address header files

This uses the new SCRFile changes to generate a header file containing a list
of all the SCRs in a core to remove the magic constant "63" (the HTIF clock
divider control register) and replace it with a generated number (which is
still 63).

vsim/Makefrag

@@ -40,6 +40,7 @@ VCS_OPTS = -notice -line +lint=all,noVCDE,noONGS,noUI -error=PCWM-L -timescale=1
 	-CC "-std=c++11" \
 	-CC "-Wl,-rpath,$(RISCV)/lib" \
 	-CC "-include $(consts_header)" \
+	-CC "-include $(scr_header)" \
 	-e vcs_main \
 	$(RISCV)/lib/libfesvr.so \
 	$(sim_dir)/libdramsim.a \