[Buildroot] [PATCH for-next] Makefile: delete default rules

[Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>]

We don't use the default implicit rules that are added by make, so
they just slow down the Makefile processing. The default implicit
rules can be removed by defining an empty .SUFFIXES: target.

This speeds up the start of the build on my machine from 5.6s to
4.9s.

Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
---
 Makefile | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/Makefile b/Makefile
index 4ea64b3..6cf5f1c 100644
--- a/Makefile
+++ b/Makefile
@@ -24,6 +24,9 @@
 # You shouldn't need to mess with anything beyond this point...
 #--------------------------------------------------------------
 
+# Delete default rules. We don't use them. This saves a bit of time.
+.SUFFIXES:
+
 # we want bash as shell
 SHELL := $(shell if [ -x "$$BASH" ]; then echo $$BASH; \
 	 else if [ -x /bin/bash ]; then echo /bin/bash; \
-- 
2.9.3