xtensa: delete __cpuinit usage from all xtensa files

The __cpuinit type of throwaway sections might have made sense
some time ago when RAM was more constrained, but now the savings
do not offset the cost and complications.  For example, the fix in
commit 5e427ec2 ("x86: Fix bit corruption at CPU resume time")
is a good example of the nasty type of bugs that can be created
with improper use of the various __init prefixes.

After a discussion on LKML[1] it was decided that cpuinit should go
the way of devinit and be phased out.  Once all the users are gone,
we can then finally remove the macros themselves from linux/init.h.

Note that some harmless section mismatch warnings may result, since
notify_cpu_starting() and cpu_up() are arch independent (kernel/cpu.c)
are flagged as __cpuinit  -- so if we remove the __cpuinit from
arch specific callers, we will also get section mismatch warnings.
As an intermediate step, we intend to turn the linux/init.h cpuinit
content into no-ops as early as possible, since that will get rid
of these warnings.  In any case, they are temporary and harmless.

This removes all the arch/xtensa uses of the __cpuinit macros from
all C files.  Currently xtensa does not have any __CPUINIT used in
assembly files.

[1] https://lkml.org/lkml/2013/5/20/589

Cc: Chris Zankel <chris@zankel.net>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: linux-xtensa@linux-xtensa.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

arch/xtensa/kernel/time.c

@@ -162,7 +162,7 @@ irqreturn_t timer_interrupt (int irq, void *dev_id)
 }
 
 #ifndef CONFIG_GENERIC_CALIBRATE_DELAY
-void __cpuinit calibrate_delay(void)
+void calibrate_delay(void)
 {
 	loops_per_jiffy = CCOUNT_PER_JIFFY;
 	printk("Calibrating delay loop (skipped)... "