net: aquantia: Increase descriptor ring size to 256

Increase AQC descriptor ring sizes for IPA to 256 to prevent
data stalls on transmit path.

CRs-Fixed: 2421992
Change-Id: Ic0afa6e7d72a2f6ec30001aae457539b7578c5ea
Signed-off-by: Jinesh K. Jayakumar <jineshk@codeaurora.org>