librdkafka: upgrade 2.11.1 -> 2.15.0

Changelog:
https://github.com/confluentinc/librdkafka/blob/v2.15.0/CHANGELOG.md

Signed-off-by: Ankur Tyagi <ankur.tyagi85@gmail.com>
Signed-off-by: Khem Raj <khem.raj@oss.qualcomm.com>

meta-oe/recipes-support/librdkafka/librdkafka_2.15.0.bb

@@ -8,7 +8,7 @@ LICENSE = "BSD-2-Clause"
 LIC_FILES_CHKSUM = "file://LICENSE;md5=40b04809b5d6f648f20f45143cbcb1ad"
 
 SRC_URI = "git://github.com/edenhill/librdkafka;protocol=https;branch=master;tag=v${PV}"
-SRCREV = "69b1865efdc0118cd017760d038d34e52fb3f0d0"
+SRCREV = "9a94e11452cdeb0a844db44ee5dd01ccbe17d3ab"
 
 UPSTREAM_CHECK_GITTAGREGEX = "v(?P<pver>\d+(\.\d+)+)"