drm: renesas: shmobile: Rename input clocks

Prepare for DT bindings by using more appropriate names for the input
clocks.

Note that all LDDCKR_ICKSEL_* definitions but the one for the bus clock
are valid only for SH7724, so the clock selection code needs to be
updated when extending clock support to other SoCs.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
[geert: Add note]
Reviewed-by: Sui Jingfeng <suijingfeng@loongson.cn>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/d4b4d2164541ae055d10064103db3c2d6540e846.1694767209.git.geert+renesas@glider.be

drivers/gpu/drm/renesas/shmobile/shmob_drm_drv.c

@@ -74,15 +74,15 @@ static int shmob_drm_setup_clocks(struct shmob_drm_device *sdev,
 
 	switch (clksrc) {
 	case SHMOB_DRM_CLK_BUS:
-		clkname = "bus_clk";
+		clkname = "fck";
 		sdev->lddckr = LDDCKR_ICKSEL_BUS;
 		break;
 	case SHMOB_DRM_CLK_PERIPHERAL:
-		clkname = "peripheral_clk";
+		clkname = "media";
 		sdev->lddckr = LDDCKR_ICKSEL_MIPI;
 		break;
 	case SHMOB_DRM_CLK_EXTERNAL:
-		clkname = NULL;
+		clkname = "lclk";
 		sdev->lddckr = LDDCKR_ICKSEL_HDMI;
 		break;
 	default: