Revert "sunxi: binman: Add U-Boot binary size check"

This reverts commit 819f1e08

.

This check was introduced in order to cope with the size limitation we had
when we were still using the raw environment in MMC. However, this
introduces padding as well, which can result in an overly huge binary if
one wants to flash the environment to some other location.

Since we now have a FAT-based environment, this check is not so useful
anymore, so we can just drop it.

Cc: Andre Przywara <andre.przywara@arm.com>
Cc: Måns Rullgård <mans@mansr.com>
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
Reviewed-by: Jagan Teki <jagan@openedev.com>