Define LOG_CATEGORY for all uclass to allow filtering with
log command.

Signed-off-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

This has the uclass enforce calling detect() before other methods.  This
allows drivers to cache information in detect() and perform (cheaper)
retrieval in the other accessors. This also modifies the only instance
where this sequencing was not followed.

Signed-off-by: Sean Anderson <sean.anderson@seco.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

This uclass is intended to provide a way to obtain information about a
U-Boot board. But the concept of a U-Boot 'board' is the whole system,
not just one circuit board, meaning that 'board' is something of a
misnomer for this uclass.

In addition, the name 'board' is a bit overused in U-Boot and we want to
use the same uclass to provide SMBIOS information.

The obvious name is 'system' but that is so vague as to be meaningless.
Use 'sysinfo' instead, since this uclass is aimed at providing information
on the system.

Rename everything accordingly.

Note: Due to the patch delta caused by the symbol renames, this patch
shows some renamed files as being deleted in one place and created in
another.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>