implement missing identify command initilizier

[igaw]

there are bunch of nvme_init_identify_.. helper function missing:

	NVME_IDENTIFY_CNS_COMMAND_SET_STRUCTURE			= 0x1C,
	NVME_IDENTIFY_CNS_UNDERLYING_NS_LIST			= 0x1D,
	NVME_IDENTIFY_CNS_PORTS_LIST				= 0x1E,
	NVME_IDENTIFY_CNS_IOCS_IND_ID_ALLOC_NS			= 0x1F,
	NVME_IDENTIFY_CNS_SUPPORTED_CTRL_STATE_FORMATS		= 0x20,

[igaw]

libnvme/test/test.c needs also be udpated