serial: sprd: remove redundant sprd_port cleanup

[ Upstream commit 72534077 ]

We don't need to cleanup sprd_port anymore, since we've dropped the way
of using the sprd_port[] array to get port index.

Reviewed-by: Baolin Wang <baolin.wang7@gmail.com>
Signed-off-by: Chunyan Zhang <chunyan.zhang@unisoc.com>
Link: https://lore.kernel.org/r/20200318105049.19623-3-zhang.lyra@gmail.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Stable-dep-of: f9608f18 ("serial: sprd: Assign sprd_port after initialized to avoid wrong access")
Signed-off-by: Sasha Levin <sashal@kernel.org>