sparc64: fix sparse warnings in smp_64.c

Fix following warnings:
smp_64.c:88:6: warning: symbol 'smp_callin' was not declared. Should it be static?
smp_64.c:133:6: warning: symbol 'cpu_panic' was not declared. Should it be static?
smp_64.c:187:6: warning: symbol 'smp_synchronize_tick_client' was not declared. Should it be static?
smp_64.c:821:18: warning: symbol 'smp_call_function_client' was not declared. Should it be static?
smp_64.c:827:18: warning: symbol 'smp_call_function_single_client' was not declared. Should it be static?
smp_64.c:964:18: warning: symbol 'smp_new_mmu_context_version_client' was not declared. Should it be static?
smp_64.c:1149:6: warning: symbol 'smp_capture' was not declared. Should it be static?
smp_64.c:1171:6: warning: symbol 'smp_release' was not declared. Should it be static?
smp_64.c:1190:18: warning: symbol 'smp_penguin_jailcell' was not declared. Should it be static?
smp_64.c:1410:18: warning: symbol 'smp_receive_signal_client' was not declared. Should it be static?

Add prototypes in kernel.h or asm/smp_64.h as appropriate.
Delete duplicate function kimage_addr_to_ra(), and
adapt parameter to const void * to match the broader use.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>