ccache: don't symlink cpp to ccache

The example in man ccache(1) suggests that ccache can
not act as a C preprocessor, thus remove the symlinks
for cpp and <arch>-cpp to /usr/bin/ccache.

srcpkgs/ccache/template

@@ -1,7 +1,7 @@
 # Template file for 'ccache'
 pkgname=ccache
 version=3.2.4
-revision=1
+revision=2
 bootstrap=yes
 build_style=gnu-configure
 makedepends="zlib-devel"
@@ -20,7 +20,7 @@ post_configure() {
 
 post_install() {
 	vmkdir usr/lib/ccache/bin
-	for f in gcc cc c++ cpp g++; do
+	for f in gcc cc c++ g++; do
 		ln -sfr ${DESTDIR}/usr/bin/ccache ${DESTDIR}/usr/lib/ccache/bin/${f}
 		for x in arm-linux-gnueabi arm-linux-gnueabihf armv7l-linux-gnueabihf \
 			arm-linux-musleabihf armv7l-linux-musleabihf; do