msm: ipa: fix aggregation calculation for > 16k

IPA driver sets the buffer size for downlink packets based
on the parameters from RMNET_IOCTL_INGRESS_FORMAT_AGG_DATA
and the hardware maximum for aggregation size and aggregation count.
The driver first makes sure that the aggregation size can be configured
based ogn the buffer size and then adjusts the buffer size to be
a power of two. IPA HW currently supports up to 31KB of aggregation,
which makes the buffer size calculation to be 16KB.

This commit changes the logic in IPA driver to allocate buffer size based
on RMNET_IOCTL_INGRESS_FORMAT_AGG_DATA parameters, and configurs the IPA HW
aggregation size to be the biggest it can support to fit the buffer.

CRs-Fixed: 2202013
Acked-by: Ady Abraham <adya@qti.qualcomm.com>
Change-Id: I1b01a7890fab378a436d4d1d44f79709ffd8a441
Signed-off-by: Skylar Chang <chiaweic@codeaurora.org>