f2fs: enforce single zone capacity

[ Upstream commit b771aadc ]

In order to simplify the complicated per-zone capacity, let's support
only one capacity for entire zoned device.

Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Stable-dep-of: 0b37ed21 ("f2fs: apply zone capacity to all zone type")
Signed-off-by: Sasha Levin <sashal@kernel.org>