msm: ipa3: use user parameter for GSI ring len

Calculate GSI ring length based on the input parameter to
setup pipe API.

Change-Id: I151400624f374262a955a04d211a96c43feb6d98
CRs-Fixed: 996292
Acked-by: Ady Abraham <adya@qti.qualcomm.com>
Signed-off-by: Skylar Chang <chiaweic@codeaurora.org>