MIPS: traps: tidy up ebase calculation

Rather than #ifdef on CONFIG_KVM_GUEST & redefine the guest kseg0 base
locally, make use of the CAC_BASE macro which has the correct value in
both cases.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Cc: Maciej W. Rozycki <macro@linux-mips.org>
Cc: linux-kernel@vger.kernel.org
Cc: Markos Chandras <markos.chandras@imgtec.com>
Patchwork: https://patchwork.linux-mips.org/patch/11183/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/kernel/traps.c

@@ -37,6 +37,7 @@
 #include <linux/irq.h>
 #include <linux/perf_event.h>
 
+#include <asm/addrspace.h>
 #include <asm/bootinfo.h>
 #include <asm/branch.h>
 #include <asm/break.h>
@@ -2204,12 +2205,8 @@ void __init trap_init(void)
 		ebase = (unsigned long)
 			__alloc_bootmem(size, 1 << fls(size), 0);
 	} else {
-#ifdef CONFIG_KVM_GUEST
-#define KVM_GUEST_KSEG0     0x40000000
-        ebase = KVM_GUEST_KSEG0;
-#else
-        ebase = CKSEG0;
-#endif
+		ebase = CAC_BASE;
+
 		if (cpu_has_mips_r2_r6)
 			ebase += (read_c0_ebase() & 0x3ffff000);
 	}