usb_storage wouldn't compile when the CONFIG_SYS_64BIT_LBA option is
turned on because the used fixed size data types in their exported
functions when they should have used lbaint_t for the block count
parameter. That meant that when the sizes happened to be the same, when
using a 28 bit LBA, the driver would build, but when it wasn't, a 48 bit
LBA, things broke.

This change adjusts the signatures to use the right type and makes small
adjustments in the affected functions.

Signed-off-by: Gabe Black <gabeblack@chromium.org>
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Marek Vasut <marex@denx.de>