MIPS: ath79: Correctly name the defines for the PLL_FB register

This register is named PLL_FB and is not a divider but a multiplier.
To make things less confusing rename the ARxxxx_PLL_DIV_SHIFT and
ARxxxx_PLL_DIV_MASK macros to ARxxxx_PLL_FB_SHIFT and
ARxxxx_PLL_FB_MASK.

Signed-off-by: Alban Bedel <albeu@free.fr>
Cc: linux-mips@linux-mips.org
Cc: Andrew Bresticker <abrestic@chromium.org>
Cc: Qais Yousef <qais.yousef@imgtec.com>
Cc: Wolfram Sang <wsa@the-dreams.de>
Cc: Sergey Ryazanov <ryazanov.s.a@gmail.com>
Cc: Gabor Juhos <juhosg@openwrt.org>
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/9772/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/ath79/clock.c b/arch/mips/ath79/clock.c
index 26479f4..226ddf0 100644
--- a/arch/mips/ath79/clock.c
+++ b/arch/mips/ath79/clock.c
@@ -62,7 +62,7 @@
 
 	pll = ath79_pll_rr(AR71XX_PLL_REG_CPU_CONFIG);
 
-	div = ((pll >> AR71XX_PLL_DIV_SHIFT) & AR71XX_PLL_DIV_MASK) + 1;
+	div = ((pll >> AR71XX_PLL_FB_SHIFT) & AR71XX_PLL_FB_MASK) + 1;
 	freq = div * ref_rate;
 
 	div = ((pll >> AR71XX_CPU_DIV_SHIFT) & AR71XX_CPU_DIV_MASK) + 1;
@@ -96,7 +96,7 @@
 	ref_rate = AR724X_BASE_FREQ;
 	pll = ath79_pll_rr(AR724X_PLL_REG_CPU_CONFIG);
 
-	div = ((pll >> AR724X_PLL_DIV_SHIFT) & AR724X_PLL_DIV_MASK);
+	div = ((pll >> AR724X_PLL_FB_SHIFT) & AR724X_PLL_FB_MASK);
 	freq = div * ref_rate;
 
 	div = ((pll >> AR724X_PLL_REF_DIV_SHIFT) & AR724X_PLL_REF_DIV_MASK);
@@ -132,7 +132,7 @@
 	ref_rate = AR913X_BASE_FREQ;
 	pll = ath79_pll_rr(AR913X_PLL_REG_CPU_CONFIG);
 
-	div = ((pll >> AR913X_PLL_DIV_SHIFT) & AR913X_PLL_DIV_MASK);
+	div = ((pll >> AR913X_PLL_FB_SHIFT) & AR913X_PLL_FB_MASK);
 	freq = div * ref_rate;
 
 	cpu_rate = freq;