mfd: cros ec: spi: Increase wait time to 200ms

This is a sucky change to bump up the time we'll wait for the EC.  Why
is it sucky?  If 200ms for a transfer is a common thing it will have a
massively bad impact on keyboard responsiveness.

It still seems like a good idea to do this, though, because we have a
gas gauge that claims that in an extreme case it could stretch the i2c
clock for 144ms.  It's not a common case so it shouldn't affect
responsiveness, but it can happen.  It's much better to have a single
slow keyboard response than to start returning errors when we don't
have to.

In newer EC designs we should probably implement a virtual battery to
respond to the kernel to insulate the kernel from these types of
issues.

Signed-off-by: Doug Anderson <dianders@chromium.org>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>