MIPS: Get rid of 'kgdb_early_setup' cruft.

Commit 854700115ecf ([MIPS] kgdb: add arch support for the kernel's kgdb core)
added the 'kgdb_early_setup' flag to avoid  calling trap_init() and init_IRQ()
the second time, however the code that called these functions earlier,  from
kgdb_arch_init(), had been already removed by that  time,  so the flag never
served any useful purpose. Remove the related code along with ugly #ifdef'ery
at last.

[ralf@linux-mips.org: Folded in Guenter Roeck's fix.]

Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Patchwork: https://patchwork.linux-mips.org/patch/10501/
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Patchwork: https://patchwork.linux-mips.org/patch/10533/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/kernel/kgdb.c

@@ -378,10 +378,6 @@ int kgdb_arch_handle_exception(int vector, int signo, int err_code,
 
 struct kgdb_arch arch_kgdb_ops;
 
-/*
- * We use kgdb_early_setup so that functions we need to call now don't
- * cause trouble when called again later.
- */
 int kgdb_arch_init(void)
 {
 	union mips_instruction insn = {