sched: walt: fix load_to_freq() for 32 bit system

The division in load_to_freq() gives a linker error on a 32 bit
system due to implicit division of 64 bit quantities. The load
and original capacity values are scaled to 1024, so make them
unsigned int.

Change-Id: I2f01c2f0779b2c821ddaa2fca5256276c6d30ef1
Signed-off-by: Pavankumar Kondeti <pkondeti@codeaurora.org>