pitx-imx8m: enable ums support

- Enable ums (USB Mass Storage) support that allows to mount onboard
  mass storage devices like eMMC and SD card on external host machine.
  This can be a convenient method to install software on onboard devices.
- Remove configuration settings duplicated (and outdated) in pitx-imx8.h
  config file.
Signed-off-by: Thomas Schaefer <thomas.schaefer@kontron.com>

configs/pitx-imx8m_defconfig

@@ -29,7 +29,10 @@ CONFIG_CMD_MEMTEST=y
 CONFIG_CMD_GPIO=y
 CONFIG_CMD_I2C=y
 CONFIG_CMD_MMC=y
+CONFIG_CMD_READ=y
 CONFIG_CMD_SF=y
+CONFIG_CMD_USB=y
+CONFIG_CMD_USB_MASS_STORAGE=y
 CONFIG_CMD_DHCP=y
 CONFIG_CMD_MII=y
 CONFIG_CMD_PING=y
@@ -86,6 +89,7 @@ CONFIG_USB_XHCI_HCD=y
 CONFIG_USB_XHCI_DWC3=y
 CONFIG_USB_DWC3=y
 CONFIG_USB_DWC3_GADGET=y
+CONFIG_USB_STORAGE=y
 CONFIG_USB_GADGET=y
 CONFIG_USB_GADGET_MANUFACTURER="FSL"
 CONFIG_USB_GADGET_VENDOR_NUM=0x0525

include/configs/pitx-imx8m.h

@@ -248,19 +248,6 @@
 #define CONFIG_SYS_I2C_SPEED		  100000
 
 /* USB configs */
-#ifndef CONFIG_SPL_BUILD
-
-#define CONFIG_CMD_USB
-#define CONFIG_USB_STORAGE
-
-#define CONFIG_CMD_USB_MASS_STORAGE
-#define CONFIG_USB_GADGET_MASS_STORAGE
-#define CONFIG_USB_FUNCTION_MASS_STORAGE
-
-#define CONFIG_CMD_READ
-
-#endif
-
 #define CONFIG_SERIAL_TAG
 #define CONFIG_FASTBOOT_USB_DEV 0