arm64: defconfig: enable the Alpine family

Enable the Alpine SoC family in the arm64 defconfig.
Signed-off-by: NAntoine Tenart <antoine.tenart@free-electrons.com>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NArnd Bergmann <arnd@arndb.de>

arch/arm64/configs/defconfig

@@ -30,6 +30,7 @@ CONFIG_MODULES=y
 CONFIG_MODULE_UNLOAD=y
 # CONFIG_BLK_DEV_BSG is not set
 # CONFIG_IOSCHED_DEADLINE is not set
+CONFIG_ARCH_ALPINE=y
 CONFIG_ARCH_BCM_IPROC=y
 CONFIG_ARCH_BERLIN=y
 CONFIG_ARCH_EXYNOS7=y