openpower: Add libflash package

Add a new 'libflash' package to install the libflash shared library from
Skiboot without the rest of the build depending on a certain Skiboot
version.

Signed-off-by: Sam Mendoza-Jonas <sam@mendozajonas.com>
diff --git a/openpower/package/libflash/Config.in b/openpower/package/libflash/Config.in
new file mode 100644
index 0000000..eb6f56d
--- /dev/null
+++ b/openpower/package/libflash/Config.in
@@ -0,0 +1,4 @@
+config BR2_PACKAGE_LIBFLASH
+	bool "libflash"
+	help
+	  Build libflash shared library