davinci: make PCM platform devices static

Make the PCM device structures used in devices.c
and devices-da8xx.c static as they are used only
in the respective files.

This was found when trying to build a single image
for DaVinci and DA8x devices using runtime P2V support.

Signed-off-by: Sekhar Nori <nsekhar@ti.com>

diff --cc arch/arm/mach-davinci/devices-da8xx.c
Simple merge

diff --cc arch/arm/mach-davinci/devices.c
Simple merge