ARM: OMAP2+: Fix SoC detection for dra62x j5-eco

We can boot dra62x j5-eco using the dm814x code as the clocks and
devices are mapped in the device tree. The dra62x is also known
as jacinto 5 eco.

We may want to add separate soc_is macros for dra62x if needed,
but this gets us to the point where we can boot dra62x with just
dts changes.

Let's also print out the unknown hawkeye register to make things
a bit easier for new SoC variants.

Signed-off-by: Tony Lindgren <tony@atomide.com>