mmc: fsl_esdhc: add compatible for fsl, imxrt-usdhc

Add compatible "fsl,imxrt-usdhc" to make mmc working on i.MXRT platforms
with CONFIG_DM_MMC=y.

Signed-off-by: Giulio Benetti <giulio.benetti@benettiengineering.com>
diff --git a/drivers/mmc/Kconfig b/drivers/mmc/Kconfig
index 85fd190..2bc19dd 100644
--- a/drivers/mmc/Kconfig
+++ b/drivers/mmc/Kconfig
@@ -732,7 +732,7 @@
 
 config FSL_USDHC
 	bool "Freescale/NXP i.MX uSDHC controller support"
-	depends on MX6 || MX7 ||ARCH_MX7ULP || IMX8 || IMX8M || TARGET_S32V234EVB
+	depends on MX6 || MX7 ||ARCH_MX7ULP || IMX8 || IMX8M || IMXRT || TARGET_S32V234EVB
 	select FSL_ESDHC_IMX
 	help
 	  This enables the Ultra Secured Digital Host Controller enhancements