rtw88: 8822[bc]: Make tables const, reduce data object size

Reduce the data size 2kb or 3kb by making tables const.
Add const to pointer declarations to make compilation work too.

(x86-64 defconfig)
$ size drivers/net/wireless/realtek/rtw88/rtw8822?.o*
   text	   data	    bss	    dec	    hex	filename
  25054	    672	      8	  25734	   6486	drivers/net/wireless/realtek/rtw88/rtw8822b.o.new
  23870	   1872	      8	  25750	   6496	drivers/net/wireless/realtek/rtw88/rtw8822b.o.old
  53646	    828	      0	  54474	   d4ca	drivers/net/wireless/realtek/rtw88/rtw8822c.o.new
  52846	   1652	      0	  54498	   d4e2	drivers/net/wireless/realtek/rtw88/rtw8822c.o.old

(x86-64 allyesconfig)
$ size drivers/net/wireless/realtek/rtw88/rtw8822?.o*
   text	   data	    bss	    dec	    hex	filename
  45811	   6280	    128	  52219	   cbfb	drivers/net/wireless/realtek/rtw88/rtw8822b.o.new
  44211	   7880	    128	  52219	   cbfb	drivers/net/wireless/realtek/rtw88/rtw8822b.o.old
 100195	   8128	      0	 108323	  1a723	drivers/net/wireless/realtek/rtw88/rtw8822c.o.new
  98947	   9376	      0	 108323	  1a723	drivers/net/wireless/realtek/rtw88/rtw8822c.o.old

Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Yan-Hsuan Chuang <yhchuang@realtek.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>