In routine configure_dma(), if transfer->len = PAGE_SIZE, then pages is one more
than required. While leads to one more sg getting allocated.

This is wrong. Correct this to allocate correct number of sg.
Signed-off-by: NViresh Kumar <viresh.kumar@st.com>
Tested-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>