[PATCH] serdev: fix builds with CONFIG_SERIAL_DEV_BUS=m

[Uwe Kleine-KÃnig]

Commit 54edb425346a ("serdev: simplify Makefile") broke builds with
serdev configured as module. I don't understand it completely yet, but
it seems that

	obj-$(CONFIG_SERIAL_DEV_BUS) += serdev/

in drivers/tty/Makefile with CONFIG_SERIAL_DEV_BUS=m doesn't result in
code that is added using obj-y in drivers/tty/serdev/Makefile being
compiled. So instead of dropping $(CONFIG_SERIAL_DEV_BUS) in serdev's
Makefile, drop it in drivers/tty/Makefile.

Fixes: 54edb425346a ("serdev: simplify Makefile")
Reported-by: kbuild test robot <lkp@xxxxxxxxx>
Signed-off-by: Uwe Kleine-KÃnig <u.kleine-koenig@xxxxxxxxxxxxxx>
---
Hello,

as Greg already added the offending patch to tty-next I assume it is
frozen and cannot be dropped any more, so here is an incremental fix.

Best regards
Uwe

 drivers/tty/Makefile        | 2 +-
 drivers/tty/serdev/Makefile | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/tty/Makefile b/drivers/tty/Makefile
index 020b1cd9294f..6b2a21d4e0bb 100644
--- a/drivers/tty/Makefile
+++ b/drivers/tty/Makefile
@@ -16,7 +16,7 @@ obj-$(CONFIG_R3964)		+= n_r3964.o
 obj-y				+= vt/
 obj-$(CONFIG_HVC_DRIVER)	+= hvc/
 obj-y				+= serial/
-obj-$(CONFIG_SERIAL_DEV_BUS)	+= serdev/
+obj-y				+= serdev/
 
 # tty drivers
 obj-$(CONFIG_AMIGA_BUILTIN_SERIAL) += amiserial.o
diff --git a/drivers/tty/serdev/Makefile b/drivers/tty/serdev/Makefile
index f71bb931735b..078417e5b068 100644
--- a/drivers/tty/serdev/Makefile
+++ b/drivers/tty/serdev/Makefile
@@ -1,6 +1,6 @@
 # SPDX-License-Identifier: GPL-2.0
 serdev-objs := core.o
 
-obj-y += serdev.o
+obj-$(CONFIG_SERIAL_DEV_BUS) += serdev.o
 
 obj-$(CONFIG_SERIAL_DEV_CTRL_TTYPORT) += serdev-ttyport.o
-- 
2.24.0