msm: ipa3: Add support for IPA/GSI emulation system

Changes made to the IPA/GSI drivers in support of an emulation
system. The emulation system is an FPGA based system that allows for
the prototyping of new IPA features before committing them to silicon.

Change-Id: I6ad6474c6574e0efb869c1b07e611d6bbd89fae8
CRs-fixed: 2204018
Acked-by: Perry Randise <prandise@qti.qualcomm.com>
Signed-off-by: Jennifer L. Zenner <jzenner@codeaurora.org>
Signed-off-by: Jie Luo <jluo@codeaurora.org>