treewide: replace LEDE_GIT with PROJECT_GIT

Remove LEDE_GIT references in favor to the new name-agnostic
PROJECT_GIT variable.

Signed-off-by: Jo-Philipp Wich <jo@mein.io>

package/libs/librpc/Makefile

@@ -4,7 +4,7 @@ PKG_NAME:=librpc
 PKG_RELEASE=1
 
 PKG_SOURCE_PROTO:=git
-PKG_SOURCE_URL=$(LEDE_GIT)/project/librpc-uclibc.git
+PKG_SOURCE_URL=$(PROJECT_GIT)/project/librpc-uclibc.git
 PKG_SOURCE_DATE:=2015-11-04
 PKG_SOURCE_VERSION:=a921e3ded051746f9f7cd5e5a312fb6771716aac
 PKG_MIRROR_HASH:=22c8dc55e1c4e8e31635a37708a3ce622a6ca33ebd918a4321b0be6ffce89b21

package/libs/libubox/Makefile

@@ -4,7 +4,7 @@ PKG_NAME:=libubox
 PKG_RELEASE=1
 
 PKG_SOURCE_PROTO:=git
-PKG_SOURCE_URL=$(LEDE_GIT)/project/libubox.git
+PKG_SOURCE_URL=$(PROJECT_GIT)/project/libubox.git
 PKG_SOURCE_DATE:=2018-01-07
 PKG_SOURCE_VERSION:=1c08e80313fd487112c48346889cc57badeef751
 PKG_MIRROR_HASH:=58cad98de55d44d7791e5d49b809ac5c32d3e6c481dc385b10e02386853f2263

package/libs/uclient/Makefile

@@ -4,7 +4,7 @@ PKG_NAME:=uclient
 PKG_RELEASE=1
 
 PKG_SOURCE_PROTO:=git
-PKG_SOURCE_URL=$(LEDE_GIT)/project/uclient.git
+PKG_SOURCE_URL=$(PROJECT_GIT)/project/uclient.git
 PKG_SOURCE_DATE:=2017-11-02
 PKG_SOURCE_VERSION:=4b87d83160fec70d50b7fcd736a8c538c28a016c
 PKG_MIRROR_HASH:=4bbb4d5f295ebdcd67fec87a6794168bea2176a42cb2907c47d8566fb33dafb3

package/libs/ustream-ssl/Makefile

@@ -4,7 +4,7 @@ PKG_NAME:=ustream-ssl
 PKG_RELEASE:=2
 
 PKG_SOURCE_PROTO:=git
-PKG_SOURCE_URL=$(LEDE_GIT)/project/ustream-ssl.git
+PKG_SOURCE_URL=$(PROJECT_GIT)/project/ustream-ssl.git
 PKG_SOURCE_DATE:=2016-07-02
 PKG_SOURCE_VERSION:=ec80adaa1b47f28d426fa19c692011ce60b992d6
 PKG_MIRROR_HASH:=bfbad6b4e8c1e933f0bfaab43cbdd44a536c08128c3a779e6f2395a6a886aab7