arm64/arch_timer: include <linux/percpu.h>

arch_timer.h includes linux/smp.h since the commit:

6acc71ccac7187fc ("arm64: arch_timer: Allows a CPU-specific erratum to only affect a subset of CPUs")

It was included to use DEFINE_PER_CPU(), etc. But It should have
included <linux/percpu.h> rather than <linux/smp.h>. It worked because
smp.h includes percpu.h.

The next commit will remove percpu.h from smp.h and it will break this
usage.

Explicitly include percpu.h and remove smp.h

Signed-off-by: Puranjay Mohan <[e-mail]>
Acked-by: Mark Rutland <[e-mail]>
Reviewed-by: Stephen Boyd <[e-mail]>
Reviewed-by: Anshuman Khandual <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Catalin Marinas <[e-mail]>

arch/arm64/include/asm/arch_timer.h

···
 #include <linux/bug.h>
 #include <linux/init.h>
 #include <linux/jump_label.h>
-#include <linux/smp.h>
+#include <linux/percpu.h>
 #include <linux/types.h>
 
 #include <clocksource/arm_arch_timer.h>