dynamic partitions: round partitions to BOARD_SUPER_PARTITION_ALIGNMENT

For the worst minimum_io_size for the BOM for the flash device on
the products, set BOARD_SUPER_PARTITION_ALIGNMENT so that we can
in advance get a summary from the build that the update may fail.

Test: build
Bug: 122328872
Change-Id: I95515e58e5308b7a1e637fc8c8791c0fc61e81f2