ARM/dts: omap4-sdp: pinmux configuration for audio

u-boot stopped configuring 'non essential' pins recently. The kernel needs
to configure the mux for audio needs.
Since the pinmux for these IPs are static let pinctrl to handle the mux
configuration for.
Configuring the mux for: twl6040 (audpwron, irq), McPDM, DMIC, McBSP1 and
McBSP2.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>