sh: convert to generic helpers for IPI function calls

This converts sh to use the new helpers for smp_call_function() and
friends, and adds support for smp_call_function_single(). Not tested,
but it compiles.

Acked-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig
index 9a854c8..3e7384f 100644
--- a/arch/sh/Kconfig
+++ b/arch/sh/Kconfig
@@ -688,6 +688,7 @@
 config SMP
 	bool "Symmetric multi-processing support"
 	depends on SYS_SUPPORTS_SMP
+	select USE_GENERIC_SMP_HELPERS
 	---help---
 	  This enables support for systems with more than one CPU. If you have
 	  a system with only one CPU, like most personal computers, say N. If