ath79: Consistently label info partition

ath79: Consistently label info partition

The info/product-info partition, which frequently contains MAC
adresses, is typically assigned the 'info' alias in DTS, but
then labelled with 'info', 'product-info' or 'config'.

This leads to different aliases if used for setting MAC adresses
in DTS compared to when using e.g. mtd_get_mac_binary. Occationally,
also multiple switch-case entries are used just because of different
labelling.

This patch relabels those partitions in ath79 to consistently use
'info'.

Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>