qlnxe: Report speeds in decimal format

It is more natural to read the speed in decimal format than hexadecimal
one.

Spotted this while diagnosing PR 287445,

[__ecore_configure_pf_max_bandwidth:6864(qlnx-0)]Configured MAX bandwidth to be 000061a8 Mb/sec
[__ecore_configure_pf_min_bandwidth:6922(qlnx-0)]Configured MIN bandwidth to be 750 Mb/sec

Reviewed by: kbowling
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D52376