net: octeontx2: Make sure the buffer is 128 byte aligned

The octeontx2 hardware needs the buffer to be 128 byte aligned.
But in the current implementation of napi_alloc_frag(), it can't
guarantee the return address is 128 byte aligned even the request size
is a multiple of 128 bytes, so we have to request an extra 128 bytes and
use the PTR_ALIGN() to make sure that the buffer is aligned correctly.

Fixes: 7a36e491

 ("octeontx2-pf: Use the napi_alloc_frag() to alloc the pool buffers")
Reported-by: Subbaraya Sundeep <sbhatta@marvell.com>
Signed-off-by: Kevin Hao <haokexin@gmail.com>
Tested-by: Subbaraya Sundeep <sbhatta@marvell.com>
Link: https://lore.kernel.org/r/20210121070906.25380-1-haokexin@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>