package/petitboot: prefer UTF-8 support

The petitboot UI looks much nicer in a Unicode locale:

* Items in the language selection submenu use multibyte Unicode
  characters. In other locales, they say "Unable to display text in this
  locale".

* The combination of TERM=linux with a UTF-8 locale is required to
  trigger a special-case workaround in ncurses code[1]. Without
  this, line-drawing characters in the menu look like q's.

Turn on wchar support in ncurses, and add a reminder that a UTF-8 locale
should be generated for things to look right.

[1] https://invisible-island.net/ncurses/ncurses.faq.html#no_line_drawing

Signed-off-by: Reza Arbab <arbab@linux.ibm.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>

package/petitboot/Config.in

@@ -10,6 +10,7 @@ config BR2_PACKAGE_PETITBOOT
 	select BR2_PACKAGE_ELFUTILS
 	select BR2_PACKAGE_LVM2 # devmapper
 	select BR2_PACKAGE_NCURSES
+	select BR2_PACKAGE_NCURSES_WCHAR
 	# run-time dependencies
 	select BR2_PACKAGE_KEXEC if !BR2_PACKAGE_KEXEC_LITE_ARCH_SUPPORTS
 	select BR2_PACKAGE_KEXEC_LITE if BR2_PACKAGE_KEXEC_LITE_ARCH_SUPPORTS && !BR2_PACKAGE_KEXEC
@@ -18,6 +19,9 @@ config BR2_PACKAGE_PETITBOOT
 	help
 	  Petitboot is a small kexec-based bootloader
 
+	  NOTE: petitboot looks best in a UTF-8 locale; be sure there
+	  is one listed in BR2_GENERATE_LOCALE.
+
 	  http://www.kernel.org/pub/linux/kernel/people/geoff/petitboot/petitboot.html
 
 if BR2_PACKAGE_PETITBOOT