ipc: use Kconfig options for __ARCH_WANT_[COMPAT_]IPC_PARSE_VERSION

Rather than #define the options manually in the architecture code, add
Kconfig options for them and select them there instead.  This also allows
us to select the compat IPC version parsing automatically for platforms
using the old compat IPC interface.

Reported-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/ipc/compat.c b/ipc/compat.c
index 20f92b2..ad9518e 100644
--- a/ipc/compat.c
+++ b/ipc/compat.c
@@ -118,7 +118,7 @@
 
 static inline int compat_ipc_parse_version(int *cmd)
 {
-#ifdef	__ARCH_WANT_COMPAT_IPC_PARSE_VERSION
+#ifdef	CONFIG_ARCH_WANT_COMPAT_IPC_PARSE_VERSION
 	int version = *cmd & IPC_64;
 
 	/* this is tricky: architectures that have support for the old