video: x86: Enable 32-bit graphics by default

Most x86 boards that use video make use of 32bpp graphics. Enable this by
default. This fixes missing graphics output on some x86 boards.

Also remove the unnecessary 'default n' while we are here.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig
index 4cde0ac..50ab365 100644
--- a/drivers/video/Kconfig
+++ b/drivers/video/Kconfig
@@ -38,7 +38,6 @@
 config VIDEO_BPP8
 	bool "Support 8-bit-per-pixel displays"
 	depends on DM_VIDEO
-	default n
 	help
 	  Support drawing text and bitmaps onto a 8-bit-per-pixel display.
 	  Enabling this will include code to support this display. Without
@@ -48,7 +47,6 @@
 config VIDEO_BPP16
 	bool "Support 16-bit-per-pixel displays"
 	depends on DM_VIDEO
-	default n
 	help
 	  Support drawing text and bitmaps onto a 16-bit-per-pixel display.
 	  Enabling this will include code to support this display. Without
@@ -58,7 +56,7 @@
 config VIDEO_BPP32
 	bool "Support 32-bit-per-pixel displays"
 	depends on DM_VIDEO
-	default n
+	default y if X86
 	help
 	  Support drawing text and bitmaps onto a 32-bit-per-pixel display.
 	  Enabling this will include code to support this display. Without
@@ -68,7 +66,6 @@
 config VIDEO_ANSI
 	bool "Support ANSI escape sequences in video console"
 	depends on DM_VIDEO
-	default n
 	help
 	  Enable ANSI escape sequence decoding for a more fully functional
 	  console.