drm/i915: rename CNP_RAWCLK_FRAC to CNP_RAWCLK_DEN

Although CNP names this field "Counter Fraction", what we write to the
register is really the denominator for the fractional part of the
divider, not the fractional part (and the field description even says
that). The ICP spec renamed the field to "Counter Fraction
Denominator", which makes a lot more sense. Use the more complete ICL
naming because we will merge the CNP and ICP functions into a single
one, which will introduce the concept of the numerator. That will make
a lot more sense when you read the "num/frac = den" calculation.

Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181112232313.26373-2-paulo.r.zanoni@intel.com

drivers/gpu/drm/i915/i915_reg.h

@@ -7907,8 +7907,7 @@ enum {
 #define  CNP_RAWCLK_DIV_MASK	(0x3ff << 16)
 #define  CNP_RAWCLK_DIV(div)	((div) << 16)
 #define  CNP_RAWCLK_FRAC_MASK	(0xf << 26)
-#define  CNP_RAWCLK_FRAC(frac)	((frac) << 26)
-#define  ICP_RAWCLK_DEN(den)	((den) << 26)
+#define  CNP_RAWCLK_DEN(den)	((den) << 26)
 #define  ICP_RAWCLK_NUM(num)	((num) << 11)
 
 #define PCH_DPLL_TMR_CFG        _MMIO(0xc6208)

drivers/gpu/drm/i915/intel_cdclk.c

@@ -2662,8 +2662,8 @@ static int cnp_rawclk(struct drm_i915_private *dev_priv)
 
 	rawclk = CNP_RAWCLK_DIV(divider / 1000);
 	if (fraction)
-		rawclk |= CNP_RAWCLK_FRAC(DIV_ROUND_CLOSEST(1000,
-							    fraction) - 1);
+		rawclk |= CNP_RAWCLK_DEN(DIV_ROUND_CLOSEST(1000,
+							   fraction) - 1);
 
 	I915_WRITE(PCH_RAWCLK_FREQ, rawclk);
 	return divider + fraction;
@@ -2687,7 +2687,7 @@ static int icp_rawclk(struct drm_i915_private *dev_priv)
 	}
 
 	rawclk = CNP_RAWCLK_DIV(divider) | ICP_RAWCLK_NUM(numerator) |
-		 ICP_RAWCLK_DEN(denominator);
+		 CNP_RAWCLK_DEN(denominator);
 
 	I915_WRITE(PCH_RAWCLK_FREQ, rawclk);
 	return frequency;