[source] cmake: support verbose build that shows compiler commands

[LEDE Commits]

nbd pushed a commit to source.git, branch master:
https://git.lede-project.org/796977010078c3ed4c2c1ff00e36d815b8c45aa0

commit 796977010078c3ed4c2c1ff00e36d815b8c45aa0
Author: Felix Fietkau <nbd at nbd.name>
AuthorDate: Thu Jan 12 14:32:02 2017 +0100

    cmake: support verbose build that shows compiler commands
    
    Signed-off-by: Felix Fietkau <nbd at nbd.name>
---
 tools/cmake/Makefile | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/tools/cmake/Makefile b/tools/cmake/Makefile
index c56cd40..08e5a69 100644
--- a/tools/cmake/Makefile
+++ b/tools/cmake/Makefile
@@ -29,4 +29,8 @@ HOST_CONFIGURE_VARS :=
 HOST_CONFIGURE_ARGS := \
 	--prefix=$(STAGING_DIR_HOST)
 
+ifneq ($(findstring c,$(OPENWRT_VERBOSE)),)
+  HOST_MAKE_FLAGS += VERBOSE=1
+endif
+
 $(eval $(call HostBuild))