video console: add 6x8 console font from linux

Small screens on the order of 256x144 pixels can't fit much text at 8x16,
and 4x6 is virtually illegible, so add an in-between 6x8 font from Linux.

Font data obtained from lib/fonts/font_6x8.c in the Linux kernel at commit
db65872b38dc ("lib/fonts: Remove internal symbols and macros from public
header file")

Link: db65872b38/lib/fonts/font_6x8.c
Signed-off-by: Alexey Charkov <alchark@flipper.net>

drivers/video/Kconfig

@@ -29,6 +29,13 @@ config VIDEO_FONT_4X6
 	  Provides character bitmap data in header file.
 	  When selecting multiple fonts, you may want to enable CMD_SELECT_FONT too.
 
+config VIDEO_FONT_6X8
+	bool "6 x 8 font size"
+	help
+	  Font for video console driver, 6 x 8 pixels.
+	  Provides character bitmap data in header file.
+	  When selecting multiple fonts, you may want to enable CMD_SELECT_FONT too.
+
 config VIDEO_FONT_8X16
 	bool "8 x 16 font size"
 	default y

include/video_font.h

@@ -12,6 +12,9 @@
 #if defined(CONFIG_VIDEO_FONT_4X6)
 #include <video_font_4x6.h>
 #endif
+#if defined(CONFIG_VIDEO_FONT_6X8)
+#include <video_font_6x8.h>
+#endif
 #if defined(CONFIG_VIDEO_FONT_8X16)
 #include <video_font_8x16.h>
 #endif
@@ -29,6 +32,9 @@ static struct video_fontdata __maybe_unused fonts[] = {
 #if defined(CONFIG_VIDEO_FONT_4X6)
 	FONT_ENTRY(4, 6, 4x6),
 #endif
+#if defined(CONFIG_VIDEO_FONT_6X8)
+	FONT_ENTRY(6, 8, 6x8),
+#endif
 #if defined(CONFIG_VIDEO_FONT_SUN12X22)
 	FONT_ENTRY(12, 22, 12x22),
 #endif