nfc: fdp: constify several pointers

Several functions do not modify pointed data so arguments and local
variables can be const for correctness and safety.  This allows also
making file-scope nci_core_get_config_otp_ram_version array const.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>