cpufreq: vexpress-spc: use macros instead of hardcoded values for cluster ids

A15 and A7 cluster identifiers are fixed to 0 and 1 respectively. There are
macros for the same and used in most of the places except this instance.

Lets use macros instead of hardcoded values for cluster ids even here.

Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

drivers/cpufreq/vexpress-spc-cpufreq.c

@@ -380,8 +380,9 @@ static int get_cluster_clk_and_freq_table(struct device *cpu_dev,
 		goto put_clusters;
 
 	/* Assuming 2 cluster, set clk_big_min and clk_little_max */
-	clk_big_min = get_table_min(freq_table[0]);
-	clk_little_max = VIRT_FREQ(1, get_table_max(freq_table[1]));
+	clk_big_min = get_table_min(freq_table[A15_CLUSTER]);
+	clk_little_max = VIRT_FREQ(A7_CLUSTER,
+				   get_table_max(freq_table[A7_CLUSTER]));
 
 	return 0;