pkgconfig_staging.bbclass: remove it

this is one existing for stale reason when package's own Makefile doesn't
handle .pc correctly. After previous commits to remove unnecessary inheritage
on it (sqlite3, libpng), the only remaining is libgcrypt. Libgcrypt itself
doesn't ship a .pc and poky generates one. In this case, simply move the
manual installation to its own do_install.

Then it's safe to remove this class file

Signed-off-by: Kevin Tian <kevin.tian@intel.com>

meta/classes/pkgconfig_stage.bbclass

@@ -1,9 +0,0 @@
-SYSROOT_PREPROCESS_FUNCS += "pkgconfig_sysroot_preprocess"
-
-pkgconfig_sysroot_preprocess () {
-	install -d ${SYSROOT_DESTDIR}${PKG_CONFIG_DIR}
-	for pc in `find ${S} -name '*.pc' -type f | grep -v -- '-uninstalled.pc$'`; do
-		pcname=`basename $pc`
-		cat $pc > ${SYSROOT_DESTDIR}${PKG_CONFIG_DIR}/$pcname
-	done
-}

meta/packages/libgcrypt/libgcrypt.inc

@@ -14,10 +14,16 @@ DEPENDS = "libgpg-error"
 SRC_URI = "ftp://ftp.gnupg.org/gcrypt/libgcrypt/libgcrypt-${PV}.tar.gz \
            file://add-pkgconfig-support.patch"
 
-inherit autotools binconfig pkgconfig pkgconfig_stage
+inherit autotools binconfig pkgconfig
 
 EXTRA_OECONF = "--without-pth --disable-asm --with-capabilities"
 
+# libgcrypt.pc is added locally and thus installed here
+do_install_append() {
+	install -d ${D}/${libdir}/pkgconfig
+	install -m 0644 ${S}/src/libgcrypt.pc ${D}/${libdir}/pkgconfig/
+}
+
 ARM_INSTRUCTION_SET = "arm"
 
 # move libgcrypt-config into -dev package