treewide: Tidy up semicolon after command macros

The U_BOOT_CMD_COMPLETE() macro has a semicolon at the end, perhaps
inadvertently. Some code has taken advantage of this.

Tidy this up by dropping the semicolon from the macro and adding it to
macro invocations as required.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>