Revert "elfutils: install library files for pkg-config"

This reverts commit 216397b812.

Due to:

Package ip-tiny is missing dependencies for the following libraries:
libelf.so.1
Makefile:187: recipe for target '/var/lib/buildbot/slaves/slave-lede-builds4/mips_24kc/build/sdk/bin/packages/mips_24kc/base/ip-tiny_4.19.0-6_mips_24kc.ipk' failed

Signed-off-by: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>

package/libs/elfutils/Makefile

@@ -71,9 +71,6 @@ define Build/InstallDev
 	$(CP) $(PKG_INSTALL_DIR)/usr/lib/libasm*.{a,so*} $(1)/usr/lib/
 	$(CP) $(PKG_INSTALL_DIR)/usr/lib/libdw*.{a,so*} $(1)/usr/lib/
 	$(CP) $(PKG_INSTALL_DIR)/usr/lib/libelf*.{a,so*} $(1)/usr/lib/
-	$(INSTALL_DIR) $(1)/usr/lib/pkgconfig
-	$(CP) $(PKG_INSTALL_DIR)/usr/lib/pkgconfig/libelf.pc $(1)/usr/lib/pkgconfig/
-	$(CP) $(PKG_INSTALL_DIR)/usr/lib/pkgconfig/libdw.pc $(1)/usr/lib/pkgconfig/
 endef
 
 define Package/libasm/install