Add include of unistd.h for ioctl() definition on Solaris
Clears gcc warning:
cg14_driver.c: In function ‘CG14InitCplane24’:
cg14_driver.c:669:3: warning: implicit declaration of function ‘ioctl’;
did you mean ‘iscntrl’? [-Wimplicit-function-declaration]
ioctl (pCg14->psdp->fd, CG14_SET_PIXELMODE, &bpp);
^~~~~