tty: n_smux: Increase inactivity timeout

Temporarily increase the Application processor inactivity timeout to
prevent a local inactivity timeout while the external modem is booting.
This is necessary to allow releasing a power-collapse ACK change without
breaking SMUX until the external modem changes have also been mainlined.

Once the external modem changes have been mainlined, then this timeout
will be reduced to 250ms to improve power consumption when idle.

Change-Id: Ic9e12c849dd53955c6ff4a1eaff0a2ec761ffa35
Signed-off-by: Eric Holmberg <eholmber@codeaurora.org>
diff --git a/drivers/tty/n_smux.c b/drivers/tty/n_smux.c
index 0d2fdb8..3b7ab33 100644
--- a/drivers/tty/n_smux.c
+++ b/drivers/tty/n_smux.c
@@ -46,7 +46,7 @@
 #define SMUX_WAKEUP_DELAY_MIN (1 << 15)
 
 /* inactivity timeout for no rx/tx activity */
-#define SMUX_INACTIVITY_TIMEOUT_MS 1000
+#define SMUX_INACTIVITY_TIMEOUT_MS 1000000
 
 /* RX get_rx_buffer retry timeout values */
 #define SMUX_RX_RETRY_MIN_MS (1 << 0)  /* 1 ms */