[PATCH][GAS][arm] Update Cortex-X1 feature flags

This is feature flags update for Cortex-X1 CPU.
For more information about this processor, see [0].

[0] : https://www.arm.com/products/cortex-x

gas/ChangeLog:

2020-10-05  Przemyslaw Wirkus  <przemyslaw.wirkus@arm.com>

	* config/tc-arm.c: Update Cortex-X1 feature flags.

gas/config/tc-arm.c

@@ -31595,7 +31595,7 @@ static const struct arm_cpu_option_table arm_cpus[] =
 	       ARM_ARCH_NONE,
 	       FPU_NONE),
   ARM_CPU_OPT ("cortex-x1",   "Cortex-X1",	       ARM_ARCH_V8_2A,
-	       ARM_FEATURE_CORE_HIGH (ARM_EXT2_FP16_INST),
+	       ARM_FEATURE_CORE_HIGH (ARM_EXT2_FP16_INST | ARM_EXT2_SB),
 	       FPU_ARCH_DOTPROD_NEON_VFP_ARMV8),
   ARM_CPU_OPT ("exynos-m1",	  "Samsung Exynos M1", ARM_ARCH_V8A,
 	       ARM_FEATURE_CORE_HIGH (ARM_EXT2_CRC),