add the "usemsi=1" option in modprob linux-kernel-bde with ag9064

[hans-tseng]

Hi Sir

We found that the Broadcom's MAC (TH2) initialization in ag9064 was too slow and it will take more than 5 minutes to finish it. So we add the "usemsi=1" while modprob linux-kernel-bde driver and it will speed up initialization process.

Steps to reproduce the issue:

1. modify /etc/init.d/opennsl-modules-3.16.0-5-amd64 on ag9064 with
   modprobe linux-kernel-bde dmasize=32M maxpayload=128 usemsi=1
2. re install the linux-kerenl-deb with options we added

[lguohan]

I am not familiar with this usemsi option, is this unique to you platform? we do not see such problem on another th2 platform.

[lguohan]

if you use usemsi, how long is initialization phase?

[lguohan]

suggest you to first discuss with broadcom to understand why this option solves your problem, then we can figure out how to incorporate this into sonic or if not.

[lguohan]

addressed in 7730bcf