x86/static-call: fix 32-bit build

In 32-bit x86 builds CONFIG_STATIC_CALL_INLINE isn't set, leading to
static_call_initialized not being available.

Define it as "0" in that case.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Fixes: 0ef8047b ("x86/static-call: provide a way to do very early static-call updates")
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>