[Blackfin] arch: Fix gpio label handling

early serial init also utilizes the peripheral request api - however
at this point bfin_gpio_init didn't allocate memory for the labels.
So we always have two zombies (allocated pin functions without labels)

This happens before the initcalls - We now allocate memory statically.
Define MAX_RESOURCES individually for each cpu.

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Bryan Wu <bryan.wu@analog.com>