staging: pi433: Fix indentation in rf69_enum.h

Basically just 's/    /\t/', to fix checkpatch.pl warnings:
"please, no spaces at the start of a line".

Signed-off-by: Simon Sandström <simon@nikanor.nu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>