The timer code relies on #defines from mach/iomap.h, cpu_is_*()
checks, and a global irq #define. All this makes this file
impossible to compile in a mult-target build. Therefore, make a
sys_timer struct for each SoC so that machine descriptors can
reference the correct timer. Then go through and replace all the
defines with raw values that are passed to a common
initialization function.

This paves the way to adding DT support to this code as well as
allows us to compile this file on multiple targets at the same
time.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: David Brown <davidb@codeaurora.org>