machine: cyclone5: set JFFS2_ERASEBLOCK to 64KB
machine: cyclone5: set JFFS2_ERASEBLOCK to 64KB

Signed-off-by: Chang Rebecca Swee Fun <88a153230f63157278771f6cd28877966cb40c57@intel.com>

dwesterg/meta-altera,dwesterg/meta-altera,kraj/meta-altera,kraj/meta-altera,kraj/meta-altera