Revert "uboot-sunxi: add missing type __u64"

This reverts commit 3cc57ba as it
should be fixed in commit 78cbd5a57e11 ("tools: macOS: types.h: fix
missing unsigned types").

References: #13833
Signed-off-by: Petr Štetiar <ynezz@true.cz>
(cherry picked from commit bc47613)