rename gpio.c to gpiod.c for it will conflict with rpi gpio command

guowenxue

2021-11-03 f696e95a01ee103605a9ed5fd23de58847ab9abc

tools/rpi_crosstool.tar.bz2 does not exist in tree 26095d5a7539ebae009435da0fae2d0971aa1ee3