For nearly all commands in U-Boot the '?' variable is handled the same
way with 0 meaning success, 1 meaning any failure.  Explain this in the
general rules section of the cmdline documentation (with a link to a
counter example) and then remove the redundant wording from most
commands. We retain a section about the return value in a number of
places where we are doing something such as always returning a specific
value or we have useful additional information to go along with the
normal return codes.

Signed-off-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>

Documentation:

* add generated index to table of contents
* create index entries for commands
* update Python packages used to build the documentation
* fix typos in dfu documentation

UEFI:

* split unrelated code from efi_bootmgr.c
* rename CONFIG_BOOTEFI_BOOTMGR to CONFIG_EFI_BOOTMGR
* net: tftp: remove explicit EFI configuration dependency
* fs: remove explicit EFI configuration dependency

Other:

* Add Goldfish RTC driver and make it available on RISC-V QEMU

Such a config option does not exist. Rephrase, and avoid mentioning
MEM_SUPPORT_64BIT_DATA, which is an implementation detail.

Signed-off-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk>

Add the description of CLI commands to the generated index.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>

Now that the cp command is changed to use memmove() internally, update
the documentation to explicitly state that overlapping regions are
allowed.

Signed-off-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk>

Add a man-page for the cp command.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Simon Glass <sjg@chromium.org>