OMAP2xxx clock: clk2xxx.c doesn't compile if CPUFREQ is enabled

if we enable CPUFREQ we can't build omap2 for two reasons,
one of them is fixed by the patch below.

It's failing because the __must_be_array() check in
ARRAY_SIZE() is failing and printing the following message:

arch/arm/mach-omap2/clock2xxx.c:453: error: negative width in bit-field '<anonymous>'
Signed-off-by: NFelipe Balbi <felipe.balbi@nokia.com>
[paul@pwsan.com: commit message updated; changed rate variable name]
Signed-off-by: NPaul Walmsley <paul@pwsan.com>

arch/arm/mach-omap2/clock2xxx.c

@@ -455,12 +455,15 @@ static struct cpufreq_frequency_table freq_table[ARRAY_SIZE(rate_table)];
 void omap2_clk_init_cpufreq_table(struct cpufreq_frequency_table **table)
 {
 	struct prcm_config *prcm;
+	long sys_ck_rate;
 	int i = 0;
 
+	sys_ck_rate = clk_get_rate(sclk);
+
 	for (prcm = rate_table; prcm->mpu_speed; prcm++) {
 		if (!(prcm->flags & cpu_mask))
 			continue;
-		if (prcm->xtal_speed != sys_ck.rate)
+		if (prcm->xtal_speed != sys_ck_rate)
 			continue;
 
 		/* don't put bypass rates in table */