Convert CONFIG_SUPPORT_EMMC_BOOT to Kconfig

This converts the following to Kconfig:
	CONFIG_SUPPORT_EMMC_BOOT

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/octeontx2_95xx_defconfig b/configs/octeontx2_95xx_defconfig
index 9a722b0..7bbf07b 100644
--- a/configs/octeontx2_95xx_defconfig
+++ b/configs/octeontx2_95xx_defconfig
@@ -77,6 +77,7 @@
 CONFIG_TFTP_TSIZE=y
 CONFIG_DM_I2C=y
 CONFIG_MISC=y
+CONFIG_SUPPORT_EMMC_BOOT=y
 CONFIG_MMC_HS400_SUPPORT=y
 CONFIG_MMC_OCTEONTX=y
 CONFIG_MTD=y