libiio: update to 0.12

- remove upstreamed patch
- remove dependency to libavahi-common which does not exist,
  seems that I have confused library name vs package name (fixes #5480)
(- only compile tested at the moment)

Signed-off-by: Michael Heimpold <mhei@heimpold.de>

libs/libiio/Makefile

@@ -8,12 +8,12 @@
 include $(TOPDIR)/rules.mk
 
 PKG_NAME:=libiio
-PKG_VERSION:=0.11
-PKG_RELEASE:=2
+PKG_VERSION:=0.12
+PKG_RELEASE:=1
 
 PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.gz
 PKG_SOURCE_URL:=https://codeload.github.com/analogdevicesinc/libiio/tar.gz/v$(PKG_VERSION)?
-PKG_HASH:=0174111b028d84f18fb3716b22834a372a1f2575938f87e20e5cbd76747d0fdb
+PKG_HASH:=36e164fc00535762c819db209928ee2704fc81657d41060ea47873bccfd5c4bc
 
 PKG_LICENSE:=LGPL-2.1
 PKG_LICENSE_FILES:=COPYING.txt
@@ -34,7 +34,7 @@ define Package/libiio
   TITLE:=Library for interfacing with Linux IIO devices
   URL:=https://github.com/analogdevicesinc/libiio
   DEPENDS:=+PACKAGE_libaio:libaio +PACKAGE_libusb-1.0:libusb-1.0 \
-           +PACKAGE_libavahi-common:libavahi-common +PACKAGE_libavahi-client:libavahi-client +libxml2
+           +PACKAGE_libavahi-client:libavahi-client +libxml2
 endef
 
 define Package/libiio/description

libs/libiio/patches/001-quote-strequal.patch

@@ -1,11 +0,0 @@
---- a/CMakeLists.txt	2017-10-23 22:24:46.000000000 +0200
-+++ b/CMakeLists.txt	2017-11-18 20:31:27.943838662 +0100
-@@ -111,7 +111,7 @@
- 		OUTPUT_STRIP_TRAILING_WHITESPACE
- 	)
- 
--	if (${LIBIIO_GIT_REPO} STREQUAL ${CMAKE_CURRENT_SOURCE_DIR})
-+	if ("${LIBIIO_GIT_REPO}" STREQUAL "${CMAKE_CURRENT_SOURCE_DIR}")
- 		execute_process(
- 			COMMAND ${GIT_EXECUTABLE} rev-parse --short HEAD
- 			WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}