base: sync: Include seq_file.h in sync.h

sync.h uses struct seq_file in some function table prototypes. This
causes compile failures when including the header in files that do not
otherwise include seq_file.h

Signed-off-by: Jonathan Hamilton <jonathan.hamilton@imgtec.com>
net: wireless: bcmdhd: Fix SUPPORT_PM2_ONLY option for p2p

Change-Id: I1db584aa5284adc8ab156e4690891bba3a1c3b91
Signed-off-by: Dmitry Shmidt <dimitrysh@google.com>