MIPS: Netlogic: Fix nlm_xlp2_get_pic_frequency to use ref_div

The variable ref_div is initialized to the correct divisor but not
used in the frequency calculation. This caused incorrect frequency
to be reported when the clock divisor is not 3.
Signed-off-by: NQingmin Liu <qingmin@broadcom.com>
Signed-off-by: NJayachandran C <jchandra@broadcom.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/8884/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

arch/mips/netlogic/xlp/nlm_hal.c

@@ -410,7 +410,7 @@ static unsigned int nlm_xlp2_get_pic_frequency(int node)
 
 	fdiv = fdiv/(1 << 13);
 	pll_out_freq_num = ((ref_clk >> 1) * (6 + mdiv)) + fdiv;
-	pll_out_freq_den = (1 << vco_post_div) * pll_post_div * 3;
+	pll_out_freq_den = (1 << vco_post_div) * pll_post_div * ref_div;
 
 	if (pll_out_freq_den > 0)
 		do_div(pll_out_freq_num, pll_out_freq_den);