NFC: st21nfca: Improve read length sequence for P2P mode.

A DEP_RES with a SUPERVISOR PDU can be up to 16 bytes long.

In order to avoid useless read during p2p, extend first read
sequence to 16 and reduce third sequence to 12 to keep same
total on the full sequence.

Signed-off-by: Christophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>