msm: pcie: add the 2nd IPC logging buffer for PCIe

The burst access to PCIe config space may generate quite a few
logging messages in the current IPC logging buffer and may lose the
history of the earlier stage. However, the detailed logging during
the latest time domain is still needed for debugging. Thus, add the
second IPC logging buffer for PCIe which tracks a longer time
duration but with less detailed logging during a short time window.

Change-Id: Ic9c6598689bfec24b4cba94926b3aabecb1bcf4c
Signed-off-by: Tony Truong <truong@codeaurora.org>