fs/jffs2: refactor endianess selection to use BR2_ENDIAN
Instead of explicitly listing the sub-architectures or architectures
that are big-endian, use BR2_ENDIAN directly.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>