ARM: shmobile: bockw dts: Add "nor-jedec" compatible value

Spansion s25fl008k is compatible with "nor-jedec". Hence add the
"nor-jedec" compatible value, so the driver can bind against the generic
name, cfr. commit 8ff16cf7 ("Documentation: devicetree: m25p80:
add "nor-jedec" binding").

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>