davinci: move psc support board-->cpu

Move DaVinci PSC support from board/* to cpu/* where it belongs.
The PSC module manages clocks and resets for all DaVinci-family
SoCs, and isn't at all board-specific.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
diff --git a/cpu/arm926ejs/davinci/Makefile b/cpu/arm926ejs/davinci/Makefile
index 7f51d17..83708d8 100644
--- a/cpu/arm926ejs/davinci/Makefile
+++ b/cpu/arm926ejs/davinci/Makefile
@@ -27,7 +27,7 @@
 
 LIB	= $(obj)lib$(SOC).a
 
-COBJS	= timer.o ether.o lxt972.o dp83848.o
+COBJS	= timer.o ether.o lxt972.o dp83848.o psc.o
 SOBJS	= reset.o
 
 ifndef CONFIG_SKIP_LOWLEVEL_INIT