kernel: add missing symbol in some 4.9 subtargets

Buildbot revealed some subtargets are still missing the new symbol.

Fixes: dfbf836a52e4 ("kernel: bump 4.9 to 4.9.143")
Signed-off-by: Koen Vandeputte <[email protected]>

target/linux/brcm2708/bcm2709/config-4.9

@@ -202,6 +202,7 @@ CONFIG_GPIO_BCM_EXP=y
 CONFIG_GPIO_BCM_VIRT=y
 CONFIG_GPIO_SYSFS=y
 CONFIG_HANDLE_DOMAIN_IRQ=y
+CONFIG_HARDEN_BRANCH_PREDICTOR=y
 CONFIG_HARDIRQS_SW_RESEND=y
 CONFIG_HAS_DMA=y
 CONFIG_HAS_IOMEM=y

target/linux/layerscape/armv7/config-4.9

@@ -352,6 +352,7 @@ CONFIG_GPIO_TPS65910=y
 CONFIG_GPIO_TWL4030=y
 CONFIG_GPIO_XILINX=y
 CONFIG_HANDLE_DOMAIN_IRQ=y
+CONFIG_HARDEN_BRANCH_PREDICTOR=y
 CONFIG_HARDIRQS_SW_RESEND=y
 CONFIG_HAS_DMA=y
 CONFIG_HAS_IOMEM=y

target/linux/layerscape/armv8_32b/config-4.9

@@ -501,6 +501,7 @@ CONFIG_GPIO_TPS65910=y
 CONFIG_GPIO_TWL4030=y
 CONFIG_GPIO_XILINX=y
 CONFIG_HANDLE_DOMAIN_IRQ=y
+CONFIG_HARDEN_BRANCH_PREDICTOR=y
 CONFIG_HARDIRQS_SW_RESEND=y
 CONFIG_HAS_DMA=y
 CONFIG_HAS_IOMEM=y