package/spdlog: disable example

SPDLOG_BUILD_EXAMPLES has been renamed SPDLOG_BUILD_EXAMPLE since
version 1.4.0 and
https://github.com/gabime/spdlog/commit/bb0f3839c1e52948f2ecb66e4e0aa79740a30205

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/spdlog/spdlog.mk

@@ -11,7 +11,7 @@ SPDLOG_LICENSE_FILES = LICENSE
 SPDLOG_DEPENDENCIES = fmt
 SPDLOG_CONF_OPTS += \
 	-DSPDLOG_BUILD_TESTS=OFF \
-	-DSPDLOG_BUILD_EXAMPLES=OFF \
+	-DSPDLOG_BUILD_EXAMPLE=OFF \
 	-DSPDLOG_BUILD_BENCH=OFF \
 	-DSPDLOG_FMT_EXTERNAL=ON