meson: Add build option for tools

Add a build option to control building some of the misc tools we
have. Also set the executables to install, presumably you want
that if you're asking for the build.

v2: set 'install:' to the with_tools value, not true (Jordan)
    handle 'all' in a the comma list (Dylan)
    Add freedreno's tools (Dylan)

Reviewed-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Eric Engestrom <eric.engestrom@imgtec.com>
Reviewed-by: Dylan Baker <dylan@pnwbakers.com>
diff --git a/meson.build b/meson.build
index b61c285..b39e2f8 100644
--- a/meson.build
+++ b/meson.build
@@ -48,6 +48,10 @@
 with_asm = get_option('asm')
 with_osmesa = get_option('osmesa')
 with_swr_arches = get_option('swr-arches').split(',')
+with_tools = get_option('tools').split(',')
+if with_tools.contains('all')
+  with_tools = ['freedreno', 'glsl', 'intel', 'nir', 'nouveau']
+endif
 if get_option('texture-float')
   pre_args += '-DTEXTURE_FLOAT_ENABLED'
   message('WARNING: Floating-point texture enabled. Please consult docs/patents.txt and your lawyer before building mesa.')