* gnu/build/image.scm (make-vfat-image): Pass fs-bits as an argument and force
1kb logical sector size only if "ESP" flag is set.
(make-partition-image): Add "fat32" partition type, support explicit "fat16"
type with vfat alias.
* gnu/system/image.scm (partition->dos-type partition): Return file system IDs
for "fat16" and "fat32" partitions.
(partition->gpt-type partition): Ditto.
Signed-off-by: Mathieu Othacehe <othacehe@gnu.org>