Convert CONFIG_IMX_BOOTAUX et al to Kconfig

This converts the following to Kconfig:
   CONFIG_IMX_BOOTAUX
   CONFIG_IMX_THERMAL

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/imx8mq_cm_defconfig b/configs/imx8mq_cm_defconfig
index cf01e8d..907b1d2 100644
--- a/configs/imx8mq_cm_defconfig
+++ b/configs/imx8mq_cm_defconfig
@@ -17,6 +17,7 @@
 CONFIG_SPL_MMC=y
 CONFIG_SPL_SERIAL=y
 CONFIG_SPL=y
+CONFIG_IMX_BOOTAUX=y
 CONFIG_DISTRO_DEFAULTS=y
 CONFIG_SYS_LOAD_ADDR=0x40480000
 CONFIG_FIT=y