linux-ti33x-psp 3.1rc8: Enable usb-to-serial drivers

Enable the PL2303 usb-to-serial driver required for serial output
from the beaglebone tester.

Signed-off-by: Joel A Fernandes <joelagnel@ti.com>
Acked-by: Jason Kridner <jdk@ti.com>
Signed-off-by: Denys Dmytriyenko <denys@ti.com>

recipes-kernel/linux/linux-ti33x-psp-3.0+3.1rc/beaglebone/defconfig

@@ -2558,7 +2558,8 @@ CONFIG_USB_LIBUSUAL=y
 # USB port drivers
 #
 # CONFIG_USB_USS720 is not set
-# CONFIG_USB_SERIAL is not set
+CONFIG_USB_SERIAL=m
+CONFIG_USB_SERIAL_PL2303=m
 
 #
 # USB Miscellaneous drivers

recipes-kernel/linux/linux-ti33x-psp_3.0+3.1rc.bb

@@ -11,7 +11,7 @@ MULTI_CONFIG_BASE_SUFFIX = ""
 
 BRANCH = "master"
 SRCREV = "1955a86594526e18f03c8d62db81119ffc4ccf0f"
-MACHINE_KERNEL_PR_append = "k+gitr${SRCREV}"
+MACHINE_KERNEL_PR_append = "l+gitr${SRCREV}"
 
 COMPATIBLE_MACHINE = "(ti33x)"