bnxt_en: Fix page pool logic for page size >= 64K

[ Upstream commit f6974b4c ]

The RXBD length field on all bnxt chips is 16-bit and so we cannot
support a full page when the native page size is 64K or greater.
The non-XDP (non page pool) code path has logic to handle this but
the XDP page pool code path does not handle this.  Add the missing
logic to use page_pool_dev_alloc_frag() to allocate 32K chunks if
the page size is 64K or greater.

Fixes: 9f4b2830

 ("bnxt: XDP multibuffer enablement")
Link: https://lore.kernel.org/netdev/20230728231829.235716-2-michael.chan@broadcom.com/
Reviewed-by: Andy Gospodarek <andrew.gospodarek@broadcom.com>
Signed-off-by: Somnath Kotur <somnath.kotur@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Link: https://lore.kernel.org/r/20230731142043.58855-2-michael.chan@broadcom.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>