ARM: AM43XX: hwmod: Add rtc hwmod

The patch registers the rtc hwmod on AM437x chips.  The RTC module is
physically present on the AM438x SoC used on AM43X-EPOS-EVM, but it is
permanently disabled. A secure RTC is used instead on these devices,
where needed. Hence adding it selectively using a separate list to get
RTC Module functional on the other am43x SoCs used on am437x-gp-evm
and am437x-sk-evm.

Signed-off-by: Keerthy <j-keerthy@ti.com>
[paul@pwsan.com: cleaned up patch description]
Signed-off-by: Paul Walmsley <paul@pwsan.com>

arch/arm/mach-omap2/omap_hwmod_43xx_data.c

@@ -1020,9 +1020,21 @@ static struct omap_hwmod_ocp_if *am43xx_hwmod_ocp_ifs[] __initdata = {
 	NULL,
 };
 
+static struct omap_hwmod_ocp_if *am43xx_rtc_hwmod_ocp_ifs[] __initdata = {
+	&am33xx_l4_wkup__rtc,
+	NULL,
+};
+
 int __init am43xx_hwmod_init(void)
 {
+	int ret;
+
 	omap_hwmod_am43xx_reg();
 	omap_hwmod_init();
-	return omap_hwmod_register_links(am43xx_hwmod_ocp_ifs);
+	ret = omap_hwmod_register_links(am43xx_hwmod_ocp_ifs);
+
+	if (!ret && of_machine_is_compatible("ti,am4372"))
+		ret = omap_hwmod_register_links(am43xx_rtc_hwmod_ocp_ifs);
+
+	return ret;
 }