Blackfin arch: Fix Bug - request lines with peripheral_request_list, but don't get freed with peripheral_free_list

Remove erroneous check_gpio(ident) in peripheral_free()
Reported-by: Michael McTernan <mmcternan@airvana.com>
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>