memory: of: parse max-freq property

Passing the memory timings maximum frequency as an unit address was
a workaround and instead 'max-freq' is preferred.  Look for 'max-freq'
first and then fallback to 'reg'.
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Reviewed-by: Alim Akhtar <alim.ahtar@samsung.com>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220206135807.211767-8-krzysztof.kozlowski@canonical.com

drivers/memory/of_memory.c

@@ -212,8 +212,10 @@ static int of_lpddr3_do_get_timings(struct device_node *np,
 {
 	int ret;
 
-	/* The 'reg' param required since DT has changed, used as 'max-freq' */
-	ret = of_property_read_u32(np, "reg", &tim->max_freq);
+	ret = of_property_read_u32(np, "max-freq", &tim->max_freq);
+	if (ret)
+		/* Deprecated way of passing max-freq as 'reg' */
+		ret = of_property_read_u32(np, "reg", &tim->max_freq);
 	ret |= of_property_read_u32(np, "min-freq", &tim->min_freq);
 	ret |= of_property_read_u32(np, "tRFC", &tim->tRFC);
 	ret |= of_property_read_u32(np, "tRRD", &tim->tRRD);