m68k: coldfire/device.c: only build FEC when HW macros are defined

When CONFIG_FEC is set (due to COMPILE_TEST) along with
CONFIG_M54xx, coldfire/device.c has compile errors due to
missing MCFEC_* and MCF_IRQ_FEC_* symbols.

Make the whole FEC blocks dependent on having the HW macros
defined, rather than on CONFIG_FEC itself.

This fix is very similar to commit e6e1e7b1 ("m68k: coldfire/device.c: only build for MCF_EDMA when h/w macros are defined")

Fixes: b7ce7f0d ("m68knommu: merge common ColdFire FEC platform setup code")
To: Greg Ungerer <gerg@linux-m68k.org>
To: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: linux-m68k@lists.linux-m68k.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Antonio Quartulli <antonio@mandelbit.com>
Signed-off-by: Greg Ungerer <gerg@kernel.org>