cfi_flash: use flash_write_word instead of reimplementing it again
While at it remove some unused code and an unbalanced
enable_interrupts().
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>