target: Implement Block Device Characteristics VPD page

Implement page B1h, Block Device Characteristics, so that we can report
a medium rotation rate of 1 (non-rotating / solid state) if the
is_nonrot device attribute is set; we update the iblock backend to set
this attribute if the underlying Linux block device has its nonrot
flag set.

Signed-off-by: Roland Dreier <roland@purestorage.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

diff --cc drivers/target/target_core_cdb.c
Simple merge

diff --cc drivers/target/target_core_configfs.c
Simple merge

diff --cc drivers/target/target_core_device.c
Simple merge

diff --cc drivers/target/target_core_iblock.c
Simple merge

diff --cc include/target/target_core_base.h
Simple merge

diff --cc include/target/target_core_device.h
Simple merge

diff --cc include/target/target_core_transport.h
Simple merge