target: Convert to DIV_ROUND_UP_SECTOR_T usage for sectors / dev_max_sectors

This patch adds the new macro usage of include/linux/kernel.h:DIV_ROUND_UP_SECTOR_T
for the new DIV_ROUND_UP_ULL() usage for 32-bit architectures with unsigned long long
sector_t division in transport_allocate_data_tasks() usage for target_core_mod v4.1

Reported-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Nicholas A. Bellinger <nab@linux-iscsi.org>