doc: Fix mismerges of fm4, kinetis and kinetis_ke flash drivers

doc: Fix mismerges of fm4, kinetis and kinetis_ke flash drivers

Commit dfc6658cf98d494e066426945879b9f60bbf9678 ("Kinetis: flash
driver described in openocd.texi") inserted a kinetis section between
fm3 and lpc2000. Then commit 43ff5acd45017fd9828cc56f54b929e600956c3b
("flash: New Spansion FM4 flash driver") was merged, inserting the fm4
section between kinetis and lpc2000, instead of after fm3. Finally
kinetis_ke was added between kinetis and fm4 in commit
5396ec5dcc64354c8101f8d3f16d498ca3b10326 ("flash: Added support for
Freescale Kinetis KE family.").

Restore the alphabetical order by moving the fm4 section to before
kinetis.

Change-Id: I77e47c3cd5b2cd8570b62ff2f7be8526aaf57ad0
Signed-off-by: Andreas Färber <afaerber@suse.de>
Reviewed-on: http://openocd.zylin.com/3484
Tested-by: jenkins
Reviewed-by: Tomas Vanek <vanekt@fbl.cz>
Reviewed-by: Marc Schink <openocd-dev@marcschink.de>