[media] v4l: rcar_fdp1: use proper name for the R-Car SoC

It is 'R-Car', not 'RCar'. No code or binding changes, only descriptive text.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

drivers/media/platform/rcar_fdp1.c

 /*
- * Renesas RCar Fine Display Processor
+ * Renesas R-Car Fine Display Processor
  *
  * Video format converter and frame deinterlacer device.
  *