cnss2: Add change to update 128KB prealloc reserve pool size to 5

WLAN host driver has a new memory requirement and it expects
5 128KB prealloc buffers. Add change to update 128KB prealloc
reserve pool size to 5.

Change-Id: Iaf3162a76e73605a06e22e8547b6aa4b48768d91
Signed-off-by: Mohammed Siddiq <quic_msiddiq@quicinc.com>