am33xx: config.mk: Add support for additional secure boot image types

Depending on the boot media, different images are needed
for secure devices. The build generates u-boot*_HS_* files
as appropriate for the different boot modes.

For AM33xx devices additional image types are needed for
various SPL boot modes as the ROM checks for the name of
the boot mode in the file it loads.

Signed-off-by: Andrew F. Davis <afd@ti.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
Acked-by: Lokesh Vutla <lokeshvutla@ti.com>

arch/arm/cpu/armv7/am33xx/config.mk

@@ -12,13 +12,29 @@ ifeq ($(CONFIG_TI_SECURE_DEVICE),y)
 # For booting from SPI use
 # u-boot-spl_HS_SPI_X-LOADER to program flash
 #
-# For booting spl from all other  media
-# use u-boot-spl_HS_ISSW
+# On AM43XX:
+#
+# For booting spl from all other media use
+# u-boot-spl_HS_ISSW
+#
+# On AM33XX:
+#
+# For booting spl from NAND flash use
+# u-boot-spl_HS_X-LOADER
+#
+# For booting spl from SD/MMC/eMMC media use
+# u-boot-spl_HS_MLO
+#
+# For booting spl over UART, USB, or Ethernet use
+# u-boot-spl_HS_2ND
 #
 # Refer to README.ti-secure for more info
 #
 ALL-y	+= u-boot-spl_HS_ISSW
 ALL-$(CONFIG_SPL_SPI_SUPPORT) += u-boot-spl_HS_SPI_X-LOADER
+ALL-y += u-boot-spl_HS_X-LOADER
+ALL-y += u-boot-spl_HS_MLO
+ALL-y += u-boot-spl_HS_2ND
 else
 ALL-y	+= MLO
 ALL-$(CONFIG_SPL_SPI_SUPPORT) += MLO.byteswap