package/linux-serial-test: bump version

Give this package some love and update to the newest version. There are
no released versions, though. Therefore, use the latest commit.

Notable changes:
 - RS485 support fixes and features
 - internal loopback support

Signed-off-by: Michael Walle <michael@walle.cc>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/linux-serial-test/linux-serial-test.hash

@@ -1,3 +1,3 @@
 # Locally computed
-sha256  bfc25088e960c18e151f978b13d893dbee9a3e377e062bd56caab1bd409e4dcb  linux-serial-test-13bea838f2a7573d2a68a6d95fc9d1f153b580be.tar.gz
+sha256  bd612ad9c10cb8090765487d5e2969be09dd0d024e7215dc764e770fbb5cc9e0  linux-serial-test-bf865c37ccf9cbb1826ada61037c036dc1990b7b.tar.gz
 sha256  a2a6760c2c6fa779a635e4a7ad00f668862ebcadb2a8a57d16662543e103e08c  LICENSES/MIT

package/linux-serial-test/linux-serial-test.mk

@@ -4,7 +4,7 @@
 #
 ################################################################################
 
-LINUX_SERIAL_TEST_VERSION = 13bea838f2a7573d2a68a6d95fc9d1f153b580be
+LINUX_SERIAL_TEST_VERSION = bf865c37ccf9cbb1826ada61037c036dc1990b7b
 LINUX_SERIAL_TEST_SITE = $(call github,cbrake,linux-serial-test,$(LINUX_SERIAL_TEST_VERSION))
 LINUX_SERIAL_TEST_LICENSE = MIT
 LINUX_SERIAL_TEST_LICENSE_FILES = LICENSES/MIT