ARM: shmobile: emev2 dtsi: Use generic names for device nodes

smu -> clocks
sti -> timer
uart -> serial

All but "clocks" are defined in ePAPR v1.1.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>