fbdev: mx3fb: avoid warning about psABI change

The arm64 gcc-9 release warns about a change in the calling
conventions:

drivers/video/fbdev/mx3fb.c: In function 'sdc_init_panel':
drivers/video/fbdev/mx3fb.c:506:12: note: parameter passing for argument of type 'struct ipu_di_signal_cfg' changed in GCC 9.1
  506 | static int sdc_init_panel(struct mx3fb_data *mx3fb, enum ipu_panel panel,
      |            ^~~~~~~~~~~~~~
drivers/video/fbdev/mx3fb.c: In function '__set_par':
drivers/video/fbdev/mx3fb.c:848:7: note: parameter passing for argument of type 'struct ipu_di_signal_cfg' changed in GCC 9.1

Change the file to just pass the struct by reference, which is
unambiguous and avoids the warning.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200408162551.3928330-1-arnd@arndb.de

drivers/video/fbdev/mx3fb.c

@@ -509,7 +509,7 @@ static int sdc_init_panel(struct mx3fb_data *mx3fb, enum ipu_panel panel,
 			  uint16_t h_start_width, uint16_t h_sync_width,
 			  uint16_t h_end_width, uint16_t v_start_width,
 			  uint16_t v_sync_width, uint16_t v_end_width,
-			  struct ipu_di_signal_cfg sig)
+			  struct ipu_di_signal_cfg *sig)
 {
 	unsigned long lock_flags;
 	uint32_t reg;
@@ -591,17 +591,17 @@ static int sdc_init_panel(struct mx3fb_data *mx3fb, enum ipu_panel panel,
 
 	/* DI settings */
 	old_conf = mx3fb_read_reg(mx3fb, DI_DISP_IF_CONF) & 0x78FFFFFF;
-	old_conf |= sig.datamask_en << DI_D3_DATAMSK_SHIFT |
-		sig.clksel_en << DI_D3_CLK_SEL_SHIFT |
-		sig.clkidle_en << DI_D3_CLK_IDLE_SHIFT;
+	old_conf |= sig->datamask_en << DI_D3_DATAMSK_SHIFT |
+		sig->clksel_en << DI_D3_CLK_SEL_SHIFT |
+		sig->clkidle_en << DI_D3_CLK_IDLE_SHIFT;
 	mx3fb_write_reg(mx3fb, old_conf, DI_DISP_IF_CONF);
 
 	old_conf = mx3fb_read_reg(mx3fb, DI_DISP_SIG_POL) & 0xE0FFFFFF;
-	old_conf |= sig.data_pol << DI_D3_DATA_POL_SHIFT |
-		sig.clk_pol << DI_D3_CLK_POL_SHIFT |
-		sig.enable_pol << DI_D3_DRDY_SHARP_POL_SHIFT |
-		sig.Hsync_pol << DI_D3_HSYNC_POL_SHIFT |
-		sig.Vsync_pol << DI_D3_VSYNC_POL_SHIFT;
+	old_conf |= sig->data_pol << DI_D3_DATA_POL_SHIFT |
+		sig->clk_pol << DI_D3_CLK_POL_SHIFT |
+		sig->enable_pol << DI_D3_DRDY_SHARP_POL_SHIFT |
+		sig->Hsync_pol << DI_D3_HSYNC_POL_SHIFT |
+		sig->Vsync_pol << DI_D3_VSYNC_POL_SHIFT;
 	mx3fb_write_reg(mx3fb, old_conf, DI_DISP_SIG_POL);
 
 	map = &di_mappings[mx3fb->disp_data_fmt];
@@ -855,7 +855,7 @@ static int __set_par(struct fb_info *fbi, bool lock)
 				   fbi->var.upper_margin,
 				   fbi->var.vsync_len,
 				   fbi->var.lower_margin +
-				   fbi->var.vsync_len, sig_cfg) != 0) {
+				   fbi->var.vsync_len, &sig_cfg) != 0) {
 			dev_err(fbi->device,
 				"mx3fb: Error initializing panel.\n");
 			return -EINVAL;