arm64: Update comment regarding values in __boot_cpu_mode

The values stored in __boot_cpu_mode were changed without updating the
comment. Rectify that.

Signed-off-by: Ben Horgan <ben.horgan@arm.com>
Reviewed-by: Dave Martin <Dave.Martin@arm.com>
Link: https://lore.kernel.org/r/20250513124525.677736-1-ben.horgan@arm.com
Signed-off-by: Will Deacon <will@kernel.org>

Author: benhor01

arch/arm64/include/asm/virt.h

@@ -67,7 +67,8 @@
  * __boot_cpu_mode records what mode CPUs were booted in.
  * A correctly-implemented bootloader must start all CPUs in the same mode:
  * In this case, both 32bit halves of __boot_cpu_mode will contain the
- * same value (either 0 if booted in EL1, BOOT_CPU_MODE_EL2 if booted in EL2).
+ * same value (either BOOT_CPU_MODE_EL1 if booted in EL1, BOOT_CPU_MODE_EL2 if
+ * booted in EL2).
  *
  * Should the bootloader fail to do this, the two values will be different.
  * This allows the kernel to flag an error when the secondaries have come up.