Fix pinpad input support for passphrase modification.
* apdu.c (pcsc_keypad_verify): Have dummy Lc field with value 0. (pcsc_keypad_modify): Likewise. (pcsc_keypad_modify): It's only for ISO7816_CHANGE_REFERENCE_DATA. bConfirmPIN value is determined by the parameter p0. * app-openpgp.c (do_change_pin): The flag use_keypad should be 0 when reset_mode is on, or resetcode is on. use_keypad only makes sense for iso7816_change_reference_data_kp. * iso7816.h (iso7816_put_data_kp): Remove. (iso7816_reset_retry_counter_kp): Remove. (iso7816_reset_retry_counter_with_rc_kp): Remove. (iso7816_change_reference_data_kp): Add an argument: IS_EXCHANGE. * iso7816.c (iso7816_put_data_kp): Remove. (iso7816_reset_retry_counter_kp): Remove. (iso7816_reset_retry_counter_with_rc_kp): Remove. (iso7816_change_reference_data_kp): Add an argument: IS_EXCHANGE.