uboot-imx

gen_eth_addr: Use POSIX rand() and srand()

Replace random()/srandom() use with rand()/srand() to support
compilation with the mingw toolchain.  The rand()/srand() functions are
generally more common and are functionally equivalent to the original
random()/srandom() calls.

Signed-off-by: Peter Tyser <ptyser@xes-inc.com>