sparc32: fix sparse warnings in leon_pmc.c

Fix following warnings:
leon_pmc.c:15:14: warning: symbol 'pmc_leon_fixup_ids' was not declared. Should it be static?
leon_pmc.c:22:5: warning: symbol 'pmc_leon_need_fixup' was not declared. Should it be static?
leon_pmc.c:41:6: warning: symbol 'pmc_leon_idle_fixup' was not declared. Should it be static?
leon_pmc.c:65:6: warning: symbol 'pmc_leon_idle' was not declared. Should it be static?

Add static to definitions.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Daniel Hellstrom <daniel@gaisler.com>
Signed-off-by: David S. Miller <davem@davemloft.net>