cxgb4/cxgb4vf/csiostor: Make PCI Device ID Tables be "const"

Make PCI Device ID Tables be "const" to move them out of the data segment and
remove a redundant check on CH_PCI_DEVICE_ID_TABLE_DEFINE_BEGIN in
t4_pci_id_tbl.h to guard the contents of the include file.

Signed-off-by: Casey Leedom <leedom@chelsio.com>
Signed-off-by: Hariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>