purism/librem13v2: Select SERIRQ_CONTINUOUS_MODE

Like other devices using ENE embedded controllers, the librem13v2
requires this config option for the PS2 keyboard and mouse
(trackpad) to function properly.

Change-Id: Ifba13b93a1fe2e76b2790d1c273fd9e2b5368ab0
Signed-off-by: Matt DeVillier <matt.devillier@gmail.com>
Reviewed-on: https://review.coreboot.org/19933
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Martin Roth <martinroth@google.com>

src/mainboard/purism/librem13v2/Kconfig

@@ -9,6 +9,8 @@ config BOARD_SPECIFIC_OPTIONS # dummy
 	select HAVE_ACPI_RESUME
 	select HAVE_ACPI_TABLES
 	select SOC_INTEL_SKYLAKE
+	# Workaround for EC/KBC IRQ1
+	select SERIRQ_CONTINUOUS_MODE
 
 config IRQ_SLOT_COUNT
 	int