pinctrl: sh-pfc: Make pinmux_cfg_reg.var_field_width[] variable-length

pinmux_cfg_reg.var_field_width[] is actually a variable-length array,
terminated by a zero, and counting at most r_width entries.
Usually the number of entries is much smaller than r_width, so the
ability to catch bugs at compile time through an "excess elements in
array initializer" warning is fairly limited.

Hence make the array variable-length, decreasing kernel size slightly.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>

drivers/pinctrl/sh-pfc/sh_pfc.h

@@ -142,8 +142,7 @@ struct pinmux_cfg_reg {
  */
 #define PINMUX_CFG_REG_VAR(name, r, r_width, var_fw0, var_fwn...) \
 	.reg = r, .reg_width = r_width,	\
-	.var_field_width = (const u8 [r_width]) \
-		{ var_fw0, var_fwn, 0 }, \
+	.var_field_width = (const u8 []) { var_fw0, var_fwn, 0 }, \
 	.enum_ids = (const u16 [])
 
 struct pinmux_drive_reg_field {