treewide: Migrate CONFIG_SYS_ALT_MEMTEST to Kconfig

Migrate the CONFIG_SYS_ALT_MEMTEST option to Kconfig.

Signed-off-by: Mario Six <mario.six@gdsys.cc>
[trini: Re-run migration after also including CMD_MEMTEST]
Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/topic_miamiplus_defconfig b/configs/topic_miamiplus_defconfig
index ef91bd5..dffc04e 100644
--- a/configs/topic_miamiplus_defconfig
+++ b/configs/topic_miamiplus_defconfig
@@ -15,6 +15,7 @@
 CONFIG_SPL_STACK_R=y
 CONFIG_SYS_PROMPT="zynq-uboot> "
 CONFIG_CMD_THOR_DOWNLOAD=y
+CONFIG_CMD_MEMTEST=y
 CONFIG_CMD_DFU=y
 # CONFIG_CMD_FLASH is not set
 CONFIG_CMD_GPIO=y