openpower: Add loadkeys package to enable backtab

This is a copy of the buildroot package 'kbd', but with a custom install
command that only installs the 'loadkeys' binary, saving almost 1MB of
space.

The loadkeys command then allows us to add additional keymap definitions
during init to enable the use of Shift-Tab on the VGA console.

Signed-off-by: Samuel Mendoza-Jonas <sam@mendozajonas.com>
diff --git a/openpower/package/loadkeys/backtab-keymap b/openpower/package/loadkeys/backtab-keymap
new file mode 100644
index 0000000..953b990
--- /dev/null
+++ b/openpower/package/loadkeys/backtab-keymap
@@ -0,0 +1,10 @@
+# Enable backtab for VGA consoles
+# Thanks to http://web.mit.edu/daveg/Info/backtab-howto.txt
+
+keycode  15 = Tab   F91
+	alt     keycode  15 = Meta_Tab
+	shift   alt     keycode  15 = F92
+
+# backtab and M-backtab
+string F91 = "\033[Z"
+string F92 = "\033\033[Z"