drm/i915/tgl: Fix doc not corresponding to code

Replace PLLs names used in documentation to that used in the code.

Cc: Vandita Kulkarni <vandita.kulkarni@intel.com>
Fixes: 68ff39c3 ("drm/i915/tgl: Add new pll ids")
Signed-off-by: Anna Karas <anna.karas@intel.com>
Reviewed-by: Vandita Kulkarni <vandita.kulkarni@intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20190926123559.15717-1-anna.karas@intel.com

drivers/gpu/drm/i915/display/intel_dpll_mgr.h

@@ -147,11 +147,11 @@ enum intel_dpll_id {
 	 */
 	DPLL_ID_ICL_MGPLL4 = 6,
 	/**
-	 * @DPLL_ID_TGL_TCPLL5: TGL TC PLL port 5 (TC5)
+	 * @DPLL_ID_TGL_MGPLL5: TGL TC PLL port 5 (TC5)
 	 */
 	DPLL_ID_TGL_MGPLL5 = 7,
 	/**
-	 * @DPLL_ID_TGL_TCPLL6: TGL TC PLL port 6 (TC6)
+	 * @DPLL_ID_TGL_MGPLL6: TGL TC PLL port 6 (TC6)
 	 */
 	DPLL_ID_TGL_MGPLL6 = 8,
 };