[hwreg] Fix printing when used in the kernel

It turns out that the kernel does not support the * directive in printf.
Also the patch that added printing failed to update the rules.mk file
for the kernel.

Change-Id: I27c48a2d483822cb2bd1d3b02b6095d6c1149383

[ulib][hwreg] Add dupe field detection and printers

The space used by the printing table is optimized away by both GCC and
Clang unless you use it. A subsequent change will gate the printers on
an optional template parameter for RegisterBase to avoid cluttering
unoptimized builds, too.

Change-Id: I82016f989dc4a0a976f702ed686809a0d41dbcd5