net/bnxt: rename driver version from Cumulus to NetXtreme
net/bnxt: rename driver version from Cumulus to NetXtreme

Rename driver version from "Broadcom Cumulus driver" to
"Broadcom NetXtreme driver" to reflect this driver is applicable to
NetXtreme family beyond Cumulus.

Signed-off-by: Scott Branden <5a452465cfd3560e4237bdccbfde688383cee441@broadcom.com>
Reviewed-by: Ajit Khaparde <01965fbd61169dc18f3fb5e13de7f67d298f8924@broadcom.com>

john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk