nandsim: add id_bytes module parameter

nandsim can simulate NAND Flash which returns the ID bytes specified
by first_id_byte, ..., fourth_id_byte module parameters.

In order to simulate NAND flash which returns more than four ID bytes,
this adds id_bytes module parameter which is specified by the array of
byte like this:

 # modprobe nandsim id_bytes=0x98,0xdc,0x90,0x26,0x76,0x15,0x01,0x08 bch=1

This doesn't add fifth_id_byte, ..., seventh_id_byte module parameters,
because they are redundant.  But the existing first_id_byte, ...,
fourth_id_byte module parameters are preserved and add "(obsolete)" to
the description.

Cc: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Brian Norris <computersforpeace@gmail.com>
Cc: linux-mtd@lists.infradead.org
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>