boards: arm: Configure SDMMC disk driver default on i.MX RT boards

Configures i.MX RT boards to enable SDMMC by default when disk drivers
are enabled.

Signed-off-by: Maureen Helm <maureen.helm@nxp.com>
diff --git a/boards/arm/mimxrt1050_evk/Kconfig.defconfig b/boards/arm/mimxrt1050_evk/Kconfig.defconfig
index fbc989f..a15fe2c 100644
--- a/boards/arm/mimxrt1050_evk/Kconfig.defconfig
+++ b/boards/arm/mimxrt1050_evk/Kconfig.defconfig
@@ -12,6 +12,9 @@
 	default CODE_FLEXSPI
 endchoice
 
+config DISK_DRIVER_SDMMC
+	default y if DISK_DRIVERS
+
 config I2C
 	default y if KSCAN
 
diff --git a/boards/arm/mimxrt1060_evk/Kconfig.defconfig b/boards/arm/mimxrt1060_evk/Kconfig.defconfig
index 934a015..bf59038 100644
--- a/boards/arm/mimxrt1060_evk/Kconfig.defconfig
+++ b/boards/arm/mimxrt1060_evk/Kconfig.defconfig
@@ -13,6 +13,9 @@
 	default CODE_FLEXSPI
 endchoice
 
+config DISK_DRIVER_SDMMC
+	default y if DISK_DRIVERS
+
 config I2C
 	default y if KSCAN
 
diff --git a/boards/arm/mimxrt1064_evk/Kconfig.defconfig b/boards/arm/mimxrt1064_evk/Kconfig.defconfig
index de02b56..b5fbbfb 100644
--- a/boards/arm/mimxrt1064_evk/Kconfig.defconfig
+++ b/boards/arm/mimxrt1064_evk/Kconfig.defconfig
@@ -12,6 +12,9 @@
 	default CODE_FLEXSPI2
 endchoice
 
+config DISK_DRIVER_SDMMC
+	default y if DISK_DRIVERS
+
 config FLASH_MCUX_FLEXSPI_NOR
 	default y if FLASH
 
diff --git a/boards/arm/mm_swiftio/Kconfig.defconfig b/boards/arm/mm_swiftio/Kconfig.defconfig
index f10f449..f0b8a47 100644
--- a/boards/arm/mm_swiftio/Kconfig.defconfig
+++ b/boards/arm/mm_swiftio/Kconfig.defconfig
@@ -12,4 +12,7 @@
 	default CODE_FLEXSPI
 endchoice
 
+config DISK_DRIVER_SDMMC
+	default y if DISK_DRIVERS
+
 endif # BOARD_MM_SWIFTIO
diff --git a/samples/subsys/fs/fat_fs/boards/mimxrt1050_evk.conf b/samples/subsys/fs/fat_fs/boards/mimxrt1050_evk.conf
deleted file mode 100644
index 08e6903..0000000
--- a/samples/subsys/fs/fat_fs/boards/mimxrt1050_evk.conf
+++ /dev/null
@@ -1 +0,0 @@
-CONFIG_DISK_DRIVER_SDMMC=y
diff --git a/samples/subsys/fs/fat_fs/boards/mimxrt1060_evk.conf b/samples/subsys/fs/fat_fs/boards/mimxrt1060_evk.conf
deleted file mode 100644
index 08e6903..0000000
--- a/samples/subsys/fs/fat_fs/boards/mimxrt1060_evk.conf
+++ /dev/null
@@ -1 +0,0 @@
-CONFIG_DISK_DRIVER_SDMMC=y
diff --git a/samples/subsys/fs/fat_fs/boards/mimxrt1064_evk.conf b/samples/subsys/fs/fat_fs/boards/mimxrt1064_evk.conf
deleted file mode 100644
index 08e6903..0000000
--- a/samples/subsys/fs/fat_fs/boards/mimxrt1064_evk.conf
+++ /dev/null
@@ -1 +0,0 @@
-CONFIG_DISK_DRIVER_SDMMC=y
diff --git a/samples/subsys/fs/fat_fs/boards/mm_swiftio.conf b/samples/subsys/fs/fat_fs/boards/mm_swiftio.conf
deleted file mode 100644
index 08e6903..0000000
--- a/samples/subsys/fs/fat_fs/boards/mm_swiftio.conf
+++ /dev/null
@@ -1 +0,0 @@
-CONFIG_DISK_DRIVER_SDMMC=y