net: chelsio: cxgb2: remove unused array pci_speed

Array pci_speed is defined but is never used hence it is redundant
and can be removed.

Cleans up clang warning:
warning: 'pci_speed' defined but not used [-Wunused-const-variable=]
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/chelsio/cxgb/cxgb2.c

@@ -109,10 +109,6 @@ static int disable_msi = 0;
 module_param(disable_msi, int, 0);
 MODULE_PARM_DESC(disable_msi, "Disable Message Signaled Interrupt (MSI)");
 
-static const char pci_speed[][4] = {
-	"33", "66", "100", "133"
-};
-
 /*
  * Setup MAC to receive the types of packets we want.
  */