pinctrl: renesas: rzg2l: Validate power registers for SD and ETH

On RZ/V2H(P) SoC, the power registers for SD and ETH do not exist,
resulting in invalid register offsets.  Ensure that the register offsets
are valid before any read/write operations are performed.  If the power
registers are not available, both SD and ETH will be set to '0'.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com> # on RZ/G3S
Link: https://lore.kernel.org/r/20240530173857.164073-7-prabhakar.mahadev-lad.rj@bp.renesas.com
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>

Author: prabhakarlad

drivers/pinctrl/renesas/pinctrl-rzg2l.c

@@ -2503,8 +2503,10 @@ static int rzg2l_pinctrl_suspend_noirq(struct device *dev)
 	rzg2l_pinctrl_pm_setup_dedicated_regs(pctrl, true);
 
 	for (u8 i = 0; i < 2; i++) {
-		cache->sd_ch[i] = readb(pctrl->base + SD_CH(regs->sd_ch, i));
-		cache->eth_poc[i] = readb(pctrl->base + ETH_POC(regs->eth_poc, i));
+		if (regs->sd_ch)
+			cache->sd_ch[i] = readb(pctrl->base + SD_CH(regs->sd_ch, i));
+		if (regs->eth_poc)
+			cache->eth_poc[i] = readb(pctrl->base + ETH_POC(regs->eth_poc, i));
 	}
 
 	cache->qspi = readb(pctrl->base + QSPI);
@@ -2535,8 +2537,10 @@ static int rzg2l_pinctrl_resume_noirq(struct device *dev)
 	writeb(cache->qspi, pctrl->base + QSPI);
 	writeb(cache->eth_mode, pctrl->base + ETH_MODE);
 	for (u8 i = 0; i < 2; i++) {
-		writeb(cache->sd_ch[i], pctrl->base + SD_CH(regs->sd_ch, i));
-		writeb(cache->eth_poc[i], pctrl->base + ETH_POC(regs->eth_poc, i));
+		if (regs->sd_ch)
+			writeb(cache->sd_ch[i], pctrl->base + SD_CH(regs->sd_ch, i));
+		if (regs->eth_poc)
+			writeb(cache->eth_poc[i], pctrl->base + ETH_POC(regs->eth_poc, i));
 	}
 
 	rzg2l_pinctrl_pm_setup_pfc(pctrl);