on 64 bit architectures, the 'enum fec_type' might not be aligned and
large enough to hold a pointer.  When running barebox without MMU,
this will crash like

| i.MX8MM unique ID: dab4b7491a2c4209
| DABT (current EL) exception (ESR 0x96000061) at 0x00000000fffefeb4
| elr: 00000000ffe14c28 lr : 00000000ffe196e0
| x0 : 0000000000000002 x1 : 00000000fffefeb4
| x2 : 00000000ffe91370 x3 : 00000000bfe1b6e8
| x4 : 0000000000000000 x5 : 0000000011000000
| ...
| Call trace:
| [<ffe14c28>] (dev_get_drvdata+0xc/0x30) from [<ffe1446c>] (device_probe+0x54/0xd0)
| [<ffe1446c>] (device_probe+0x54/0xd0) from [<ffe14530>] (match+0x48/0x58)
| [<ffe14530>] (match+0x48/0x58) from [<ffe14a64>] (register_driver+0xc0/0xd0)
| [<ffe14a64>] (register_driver+0xc0/0xd0) from [<ffe01738>] (start_barebox+0x64/0x90)

Signed-off-by: Enrico Scholz <enrico.scholz@sigma-chemnitz.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>