msm: ipa: send NOP write register command before NAT_INIT imm cm0064

During NAT table re-configuration, send NOP write register
command before sending NAT_INIT immediate command to make
sure that IPH pipeline is clear.

Change-Id: Ib2a6d89b9147bf2fd93144ae9baa34a7bbd375ec
Acked-by: Sunil Kumar Paidimarri <hisunil@qti.qualcomm.com>
Signed-off-by: Skylar Chang <chiaweic@codeaurora.org>