mul-infer does not seem to build

[sorced-jim]

The mul-infer directory does not seem to build for pv1 or evt2 configs because SB_IO is trying to use 8 more slots than are available.

Output from nextpnr-ice40:

Info: Device utilisation:
Info: 	         ICESTORM_LC:  2566/ 5280    48%
Info: 	        ICESTORM_RAM:     0/   30     0%
Info: 	               SB_IO:   102/   96   106%
Info: 	               SB_GB:     1/    8    12%
Info: 	        ICESTORM_PLL:     0/    1     0%
Info: 	         SB_WARMBOOT:     0/    1     0%
Info: 	        ICESTORM_DSP:     1/    8    12%
Info: 	      ICESTORM_HFOSC:     0/    1     0%
Info: 	      ICESTORM_LFOSC:     0/    1     0%
Info: 	              SB_I2C:     0/    2     0%
Info: 	              SB_SPI:     0/    2     0%
Info: 	              IO_I3C:     0/    2     0%
Info: 	         SB_LEDDA_IP:     0/    1     0%
Info: 	         SB_RGBA_DRV:     0/    1     0%
Info: 	      ICESTORM_SPRAM:     0/    4     0%

Info: Placed 0 cells based on constraints.
ERROR: Unable to find a placement location for cell 'inpB[8]$sb_io'
139 warnings, 1 error
make: *** [Makefile:66: .build/MulInfer.asc] Error 255

$ nextpnr-ice40 --version
nextpnr-ice40 -- Next Generation Place and Route (Version 0.1-1)