pinctrl: rzn1: Make array reg_drive static, makes object smaller

pinctrl: rzn1: Make array reg_drive static, makes object smaller

Don't populate the array reg_drive on the stack but instead make it
static. Makes the object code smaller by 32 bytes.

Before:
   text	   data	    bss	    dec	    hex	filename
  31991	  15696	      0	  47687	   ba47	drivers/pinctrl/pinctrl-rzn1.o

After:
   text	   data	    bss	    dec	    hex	filename
  31863	  15792	      0	  47655	   ba27	drivers/pinctrl/pinctrl-rzn1.o

(gcc version 9.2.1, amd64)

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Link: https://lore.kernel.org/r/20191007140559.11840-1-colin.king@canonical.com
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>