soc: zte: Restrict SOC_ZTE to ARCH_ZX or COMPILE_TEST

The ZTE SoC drivers are only useful when building for a ZTE ZX platform.

Fixes: 4c2c2e39713b8cfb ("soc: zte: pm_domains: Prepare for supporting ARMv8 zx2967 family")
Signed-off-by: Geert Uytterhoeven <[e-mail]>
Reviewed-by: Baoyou Xie <[e-mail]>
Signed-off-by: Arnd Bergmann <[e-mail]>

drivers/soc/zte/Kconfig

···
 # ZTE SoC drivers
 #
 menuconfig SOC_ZTE
+	depends on ARCH_ZX || COMPILE_TEST
 	bool "ZTE SoC driver support"
 
 if SOC_ZTE