[MIPS] remove CONFIG_CPU_R4000 line from Makefile

The existing options are named CONFIG_CPU_R4300 and CONFIG_CPU_R4X00,
and they are directly below.

Reported-by: Robert P. J. Day <rpjday@crashcourse.ca>
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
1 file changed