omap4-common: fix definition of mode (it's a string, not an array of strings)

Change-Id: Ib5b58e2e3b5ae317a0eedb82e08f1dc5f85ff877
Merge pull request #4 from CyanogenMod/cm-11.0

omap4-common: fix definition of mode (it's a string, not an array of strings)