ARM: omap4: cpuidle: configure MPU C4 state to CSWR

For enabling dynamic dependency btn MPUSS <-> EMIF, device is unstable
at
with MPUSS configured to OSWR. By disabling static dep btn MPUSS
<->EMIF,
there is significant power saving seen on during active use-cases. So
hence
preventing MPUSS power domain to CSWR.

Change-Id: I63902a501997e2e9f8b7539f2f17067af0b417f1
Signed-off-by: Ambresh K <ambresh@ti.com>