tools: Add install make target for liblockdep

tools: Add install make target for liblockdep

Allow user to call "liblockdep_install" target. Also add liblockdep to "all"
and "install" targets (as "help" command suggests).

Signed-off-by: Alexander Sverdlin <alexander.sverdlin@gmail.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: a.p.zijlstra@chello.nl
Cc: ben@decadent.org.uk
Link: http://lkml.kernel.org/r/20170525130005.5947-11-alexander.levin@verizon.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>