tools: bump up timeout for polling to ~5.5 minutes
tools: bump up timeout for polling to ~5.5 minutes

Signed-off-by: Patrick Venture <36c53fa43f47f3fd67cb2fc38031827244d18a1f@google.com>
Change-Id: I384734c592e39a01c5531d3d7d6c79474c2b0b44

openbmc/phosphor-ipmi-flash