Allow distributions to specify a custom pubkeys dir

Distributions which need a custom pubkey dir can just
specify it upon build time.

Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>

Makefile

diff --git a/Makefile b/Makefile
index 6d131f9..b93b735 100644
--- a/Makefile
+++ b/Makefile
@@ -16,8 +16,11 @@
 # a different location.
 UDEV_RULE_DIR?=/lib/udev/rules.d/
 
-# Used locally to retrieve all pubkeys during build time
-PUBKEY_DIR=pubkeys
+# If your distribution requires a custom pubkeys dir
+# you must update this variable to reflect where the
+# keys are put when building. For example you can run
+# with make PUBKEY_DIR=/usr/lib/crda/pubkeys
+PUBKEY_DIR?=pubkeys
 
 CFLAGS += -Wall -g
 
@@ -81,6 +84,7 @@
 
 keys-%.c: utils/key2pub.py $(wildcard $(PUBKEY_DIR)/*.pem)
 	$(NQ) '  GEN ' $@
+	$(NQ) '  Trusted pubkeys:' $(wildcard $(PUBKEY_DIR)/*.pem)
 	$(Q)./utils/key2pub.py --$* $(wildcard $(PUBKEY_DIR)/*.pem) $@
 
 %.o: %.c regdb.h