armvirt: 64: enable driver for QEMU' supported watchdog

QEMU can emulate several watchdogs:
aspeed SoC, i6300esb, ib700wdt, imx2, cmsdk-apb and sbsa_gwdt.

Out of these, the ARM SBSA Generic Watchdog (sbsa_gwdt)
makes the most sense for the armvirt' 64 target. Both imx2 and
aspeed are guarded by special vendor specific CONFIG_ in the
upstream kernel.

Signed-off-by: Christian Lamparter <chunkeey@gmail.com>

target/linux/armvirt/64/config-5.10

@@ -36,6 +36,7 @@ CONFIG_ARM64_WORKAROUND_CLEAN_CACHE=y
 CONFIG_ARM64_WORKAROUND_REPEAT_TLBI=y
 CONFIG_ARM64_WORKAROUND_SPECULATIVE_AT=y
 CONFIG_ARM_ARCH_TIMER_OOL_WORKAROUND=y
+CONFIG_ARM_SBSA_WATCHDOG=y
 CONFIG_ATOMIC64_SELFTEST=y
 CONFIG_AUDIT_ARCH_COMPAT_GENERIC=y
 CONFIG_BACKLIGHT_CLASS_DEVICE=y
@@ -147,4 +148,5 @@ CONFIG_VEXPRESS_CONFIG=y
 CONFIG_VIDEOMODE_HELPERS=y
 CONFIG_VIRTIO_DMA_SHARED_BUFFER=y
 CONFIG_VMAP_STACK=y
+CONFIG_WATCHDOG_CORE=y
 CONFIG_ZONE_DMA32=y

target/linux/armvirt/64/config-5.15

@@ -38,6 +38,7 @@ CONFIG_ARM64_WORKAROUND_CLEAN_CACHE=y
 CONFIG_ARM64_WORKAROUND_REPEAT_TLBI=y
 CONFIG_ARM64_WORKAROUND_SPECULATIVE_AT=y
 CONFIG_ARM_ARCH_TIMER_OOL_WORKAROUND=y
+CONFIG_ARM_SBSA_WATCHDOG=y
 CONFIG_ATOMIC64_SELFTEST=y
 CONFIG_AUDIT_ARCH_COMPAT_GENERIC=y
 CONFIG_BACKLIGHT_CLASS_DEVICE=y
@@ -147,4 +148,5 @@ CONFIG_VEXPRESS_CONFIG=y
 CONFIG_VIDEOMODE_HELPERS=y
 CONFIG_VIRTIO_DMA_SHARED_BUFFER=y
 CONFIG_VMAP_STACK=y
+CONFIG_WATCHDOG_CORE=y
 CONFIG_ZONE_DMA32=y