MIPS: IP30: Remove incorrect `cpu_has_fpu' override

Remove unsupported forcing of `cpu_has_fpu' to 1, which makes the `nofpu'
kernel parameter non-functional, and also causes a link error:

ld: arch/mips/kernel/traps.o: in function `trap_init':
./arch/mips/include/asm/msa.h:(.init.text+0x348): undefined reference to `handle_fpe'
ld: ./arch/mips/include/asm/msa.h:(.init.text+0x354): undefined reference to `handle_fpe'
ld: ./arch/mips/include/asm/msa.h:(.init.text+0x360): undefined reference to `handle_fpe'

where the CONFIG_MIPS_FP_SUPPORT configuration option has been disabled.

Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Reported-by: Stephen Zhang <starzhangzsd@gmail.com>
Fixes: 7505576d ("MIPS: add support for SGI Octane (IP30)")
Cc: stable@vger.kernel.org # v5.5+
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>