soc: bcm: brcmstb: depend on ARCH_BRCMSTB over arm arches

The SOC_BRCMSTB is better depending on ARCH_BRCMSTB as it's
defined for both arm and aarch64 but is more specific to
the actual SoC's dependencies, it'll still get compile tested.
Signed-off-by: Peter Robinson <pbrobinson@gmail.com>
Link: https://lore.kernel.org/r/20231009135833.17880-2-pbrobinson@gmail.comSigned-off-by: Florian Fainelli <florian.fainelli@broadcom.com>

drivers/soc/bcm/Kconfig

@@ -33,7 +33,7 @@ config SOC_BCM63XX
 
 config SOC_BRCMSTB
 	bool "Broadcom STB SoC drivers"
-	depends on ARM || ARM64 || BMIPS_GENERIC || COMPILE_TEST
+	depends on ARCH_BRCMSTB || BMIPS_GENERIC || COMPILE_TEST
 	select SOC_BUS
 	help
 	  Enables drivers for the Broadcom Set-Top Box (STB) series of chips.