drm: meson: global clean-up

This patch aims to:
- Add general and TODO comments
- Respect coding style for multi-line comments
- Align macro definitions
- Remove useless macro

Signed-off-by: Julien Masson <jmasson@baylibre.com>
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://patchwork.freedesktop.org/patch/msgid/86pnn382e8.fsf@baylibre.com

drivers/gpu/drm/meson/meson_vclk.c

@@ -496,6 +496,7 @@ void meson_hdmi_pll_set_params(struct meson_drm *priv, unsigned int m,
 		regmap_write(priv->hhi, HHI_HDMI_PLL_CNTL, 0x0b3a0400 | m);
 
 		/* Enable and reset */
+		/* TODO: add specific macro for g12a here */
 		regmap_update_bits(priv->hhi, HHI_HDMI_PLL_CNTL,
 				   0x3 << 28, 0x3 << 28);
 
@@ -970,7 +971,8 @@ void meson_vclk_setup(struct meson_drm *priv, unsigned int target,
 		meson_venci_cvbs_clock_config(priv);
 		return;
 	} else if (target == MESON_VCLK_TARGET_DMT) {
-		/* The DMT clock path is fixed after the PLL:
+		/*
+		 * The DMT clock path is fixed after the PLL:
 		 * - automatic PLL freq + OD management
 		 * - vid_pll_div = VID_PLL_DIV_5
 		 * - vclk_div = 2