MUSB: fix DaVinci glue layer dependency

CONFIG_ARCH_DAVINCI now embraces both the "real" DaVinci and DA8xx/OMAP-L1x --
on which the DaVinci glue layer won't work. Change the Makefile dependency to
CONFIG_ARCH_DAVINCI_DMx which corresponds to "real" DaVinci.

Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Felipe Balbi <felipe.balbi@nokia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>