config_fallbacks.h has some logic that sets HAVE_BLOCK_DEVICE
based on a list of enabled options.  Moving HAVE_BLOCK_DEVICE to
Kconfig allows us to drastically shrink the logic in
config_fallbacks.h

Signed-off-by: Adam Ford <aford173@gmail.com>
[trini: Rename HAVE_BLOCK_DEVICE to CONFIG_BLOCK_DEVICE]
Signed-off-by: Tom Rini <trini@konsulko.com>

Remove an unreachable return statement.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>

There is already a macro LBAFU to aid formatted print with lbaint_t
variables. Let's use it in the common block command codes.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>

Most block devices provide a command (e.g. 'sata', 'scsi', 'ide') and
these commands generally do the same thing. This makes it harder to
maintain this code and keep it consistent.

We now have a block device interface which is either implemented by driver
model (when CONFIG_BLK is enabled) or with a legacy interface. Therefore
it is possible to handle most of what these commands do with generic code.

Add a new generic function to process block-device commands using the
interface type and the current device number for that type.

Signed-off-by: Simon Glass <sjg@chromium.org>