net: hns3: make array spec_opcode static const, makes object smaller

Don't populate the array spec_opcode on the stack but instead it
static const. Makes the object code smaller by 158 bytes:

Before:
   text   data   bss     dec    hex filename
  12271   3976   128   16375   3ff7 .../hisilicon/hns3/hns3pf/hclge_cmd.o

After:
   text   data   bss     dec    hex filename
  12017   4072   128   16217   3f59 .../hisilicon/hns3/hns3pf/hclge_cmd.o

(gcc version 10.3.0)

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>