toolchain/toolchain-external/toolchain-external-arm-aarch64: fix BR2_ARCH_NEEDS_GCC_AT_LEAST_X guard

BR2_ARCH_NEEDS_GCC_AT_LEAST_X guards has been introduced by [1] to
prevent selecting an external toolchain that did not support the GCC
arch tuning the user had selected.

But it was not changed while updating to version 13.2-rel1.

Fixes: 7b4b3c2c78034fb3b16ad9658057f05066dcc4dd

[1] eed1670d8a6f0899f5fdfc26bd6d1609ebc19c7a

Cc: Antoine Coutant <antoine.coutant@smile.fr>
Signed-off-by: Romain Naour <romain.naour@smile.fr>
Signed-off-by: Julien Olivain <ju.o@free.fr>
(cherry picked from commit 299967723354c9ad50f7faf945ac809d32bf4108)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

toolchain/toolchain-external/toolchain-external-arm-aarch64/Config.in

@@ -2,7 +2,7 @@ config BR2_TOOLCHAIN_EXTERNAL_ARM_AARCH64
 	bool "Arm AArch64 13.2.rel1"
 	depends on BR2_aarch64
 	depends on BR2_HOSTARCH = "x86_64"
-	depends on !BR2_ARCH_NEEDS_GCC_AT_LEAST_13
+	depends on !BR2_ARCH_NEEDS_GCC_AT_LEAST_14
 	select BR2_TOOLCHAIN_EXTERNAL_GLIBC
 	select BR2_TOOLCHAIN_HAS_SSP
 	select BR2_INSTALL_LIBSTDCPP