MIPS: Correct ISA masking in FPU feature determination

Correct an ISA level determination problem introduced with 8b8aa636
[MIPS: kernel: cpu-probe.c: Add support for MIPS R6], reverting explicit
masking against individual `MIPS_CPU_ISA_*' macros in FPU feature
determination.

Feature macros such as `cpu_has_mips_r' cannot be used here, because
they operate on CPU #0 and we want to refer to the current CPU instead.
They cannot be used for masking against the current CPU either because
they mask against CPU #0 too, e.g.:

# define cpu_has_mips32r1	(cpu_data[0].isa_level & MIPS_CPU_ISA_M32R1)
Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Cc: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9706/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/kernel/cpu-probe.c

@@ -1374,7 +1374,9 @@ void cpu_probe(void)
 	if (c->options & MIPS_CPU_FPU) {
 		c->fpu_id = cpu_get_fpu_id();
 
-		if (c->isa_level & cpu_has_mips_r) {
+		if (c->isa_level & (MIPS_CPU_ISA_M32R1 | MIPS_CPU_ISA_M64R1 |
+				    MIPS_CPU_ISA_M32R2 | MIPS_CPU_ISA_M64R2 |
+				    MIPS_CPU_ISA_M32R6 | MIPS_CPU_ISA_M64R6)) {
 			if (c->fpu_id & MIPS_FPIR_3D)
 				c->ases |= MIPS_ASE_MIPS3D;
 			if (c->fpu_id & MIPS_FPIR_FREP)