bus/pci: do not use kernel version to determine MSIX defines
bus/pci: do not use kernel version to determine MSIX defines

In real life, kernel version is only weakly corolated with presence
or absence of defines in header files. Instead, check directly if
the needed value is defined.

Signed-off-by: Stephen Hemminger <06fa905d7f2aaced6dc72e9511c71a2a51e8aead@networkplumber.org>

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