gpio/nomadik: fix sleepmode for elder Nomadik

The mach-nomadik machine did not compile properly due to bad
ux500-specific functions being called. Introduce new state
variables to fix this up.

Reported-by: Axel Lin <axel.lin@gmail.com>
Cc: Alessandro Rubini <rubini@unipv.it>
Cc: Prafulla Wadaskar <prafulla.wadaskar@st.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>