Show directory for SUBDIRs which also run their own targets.

[bdrewery]

Summary

To remove confusion on SUBDIRS that also have their own targets, show
a directory output before running their command. This is useful in
cases such as tests/ where 'make clean' appears to run the same command
3 times in a row, when really it is in 3 different subdirs are they are
coming back up the chain.

This became more noticeable after rS288158

Example in P77

Test Plan

cd test && make clean

[bdrewery]

Don't show the output from bsd.progs.mk which sets SUBDIR=

[bdrewery]

I should note that this is just "more noticeable" after rS288158; that commit actually FIXED these files not being cleaned.

[emaste]

Sample output in P77 looks good

[bdrewery]

I decided against this for now.