Make the default target only build the utils

The following patch adjusts the main Makefile and secondary Makefile
(Test.mk) so the default target only builds the pm-qa utils from sources,
without running the tests.

Also document some variables and targets.

2018-01-11  Luis Machado  <luis.machado@linaro.org>

	* Makefile: Document target "all".
	* README: Document how to build only the pm-qa utils.
	* Test.mk: Document misc variables and targets.
	(SRC): Hold list of all utils' .c files.
	($(EXEC)): New target to build all utils from sources.
	(check): Move target closer to uncheck target.

Signed-off-by: Luis Machado <luis.machado@linaro.org>
3 files changed