tty: n_smux: Fix scheduling while atomic issue for ldisc open/close
tty: n_smux: Fix scheduling while atomic issue for ldisc open/close

Unlock spinlock when calling platform_device functions during line
discipline (ldisc) loading an unloading.

This fixes a potential scheduling while atomic condition if the platform
device code needs to allocate memory.

Change-Id: I7dbf15dc62b2276393272392a038c1d846ea2419
Signed-off-by: Eric Holmberg <5000aa55685d659e1f7f26ece526f9c7021ab484@codeaurora.org>
Signed-off-by: David Brown <67bb63793f66c3c3797af10faa739beca3aeb927@codeaurora.org>

TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas