can: rcar_canfd: Abstract out DCFG address differences

Abstract the different addresses for the Channel n Data Bitrate
Configuration Register (DCFG) in the definition of the register macro,
like is already done for other register definitions, to simplify code
accessing this register.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/all/13e02d710dac3ddef73aa4be2b995766db9b6b4d.1674499048.git.geert+renesas@glider.beSigned-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

drivers/net/can/rcar/rcar_canfd.c

@@ -429,7 +429,6 @@
 #define RCANFD_C_RPGACC(r)		(0x1900 + (0x04 * (r)))
 
 /* R-Car V3U Classical and CAN FD mode specific register map */
-#define RCANFD_V3U_DCFG(m)		(0x1400 + (0x20 * (m)))
 #define RCANFD_V3U_FDCFG(m)		(0x1404 + (0x20 * (m)))
 
 #define RCANFD_V3U_GAFL_OFFSET		(0x1800)
@@ -437,7 +436,7 @@
 /* CAN FD mode specific register map */
 
 /* RSCFDnCFDCmXXX -> RCANFD_F_XXX(m) */
-#define RCANFD_F_DCFG(m)		(0x0500 + (0x20 * (m)))
+#define RCANFD_F_DCFG(gpriv, m)		(reg_v3u(gpriv, 0x1400, 0x0500) + (0x20 * (m)))
 #define RCANFD_F_CFDCFG(m)		(0x0504 + (0x20 * (m)))
 #define RCANFD_F_CFDCTR(m)		(0x0508 + (0x20 * (m)))
 #define RCANFD_F_CFDSTS(m)		(0x050c + (0x20 * (m)))
@@ -1346,10 +1345,7 @@ static void rcar_canfd_set_bittiming(struct net_device *dev)
 		cfg = (RCANFD_DCFG_DTSEG1(gpriv, tseg1) | RCANFD_DCFG_DBRP(brp) |
 		       RCANFD_DCFG_DSJW(sjw) | RCANFD_DCFG_DTSEG2(gpriv, tseg2));
 
-		if (is_v3u(gpriv))
-			rcar_canfd_write(priv->base, RCANFD_V3U_DCFG(ch), cfg);
-		else
-			rcar_canfd_write(priv->base, RCANFD_F_DCFG(ch), cfg);
+		rcar_canfd_write(priv->base, RCANFD_F_DCFG(gpriv, ch), cfg);
 		netdev_dbg(priv->ndev, "drate: brp %u, sjw %u, tseg1 %u, tseg2 %u\n",
 			   brp, sjw, tseg1, tseg2);
 	} else {