ipr: Increase default adapter init stage change timeout

Increase the default init stage change timeout from 15 seconds to 30 seconds.
This resolves issues we have seen with some adapters not transitioning
to the first init stage within 15 seconds, which results in adapter
initialization failures.

Cc: <stable@vger.kernel.org>
Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>