Makefile compatibility issue on Windows10 with cocotb

[mchenwang]

The issue is in this line https://github.com/adam-maj/tiny-gpu/blob/9a07e2b97f322439cf4cbaf1d53f4dc4b31c2a2a/Makefile#L8

cocotb version: 1.8.1

The lib name is cocotbvpi_icarus on Windows instead of libcocotbvpi_icarus.