The driver for fixed voltage regulater uses "regulator-fixed" for
compatible string, not "fixed-regulator".
Fixes: 102dc5a625 ("mvebu: add support for FortiGate 50E")
Signed-off-by: INAGAKI Hiroshi <musashino.open@gmail.com>
Link: https://github.com/openwrt/openwrt/pull/16409
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>