Bluetooth: Fix using PHYs bitfields as PHY value

Bluetooth: Fix using PHYs bitfields as PHY value

This renames the PHY fields in bt_iso_io_qos to PHYs (plural) since it
represents a bitfield where multiple PHYs can be set and make the same
change also to HCI_OP_LE_SET_CIG_PARAMS since both c_phy and p_phy
fields are bitfields.

This also fixes the assumption that hci_evt_le_cis_established PHYs
fields are compatible with bt_iso_io_qos, they are not, the fields in
hci_evt_le_cis_established represent just a single PHY value so they
need to be converted to bitfield when set in bt_iso_io_qos.

Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>