ti: omap5: Switch to generic distro boot for non-Android cases

Remove the environment support for various legacy boot methods.  With
this, we will now default to booting any distribution that follows the
generic distro boot framework and no longer attempt to boot various
legacy (to this SoC) scripts/etc.  Note that if we do not find anything
here we will continue to try and Android methods and will start by
trying fastboot.

Cc: Lokesh Vutla <lokeshvutla@ti.com>
Signed-off-by: Tom Rini <trini@konsulko.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Link: https://lore.kernel.org/r/20210701132612.7559-3-trini@konsulko.com

include/configs/ti_omap5_common.h

@@ -177,21 +177,13 @@
 #define DEFAULT_COMMON_BOOT_TI_ARGS \
 	"console=" CONSOLEDEV ",115200n8\0" \
 	"fdtfile=undefined\0" \
-	"bootpart=0:2\0" \
-	"bootdir=/boot\0" \
-	"bootfile=zImage\0" \
+	"finduuid=part uuid mmc 0:2 uuid\0" \
 	"usbtty=cdc_acm\0" \
 	"vram=16M\0" \
 	AVB_VERIFY_CMD \
 	"partitions=" PARTS_DEFAULT "\0" \
 	"optargs=\0" \
 	"dofastboot=0\0" \
-	"emmc_linux_boot=" \
-		"echo Trying to boot Linux from eMMC ...; " \
-		"setenv mmcdev 1; " \
-		"setenv bootpart 1:2; " \
-		"setenv mmcroot /dev/mmcblk0p2 rw; " \
-		"run mmcboot;\0" \
 	"emmc_android_boot=" \
 		"setenv mmcdev 1; " \
 		"mmc dev $mmcdev; " \
@@ -278,12 +270,18 @@
 		"run update_to_fit;"	\
 	"fi;"	\
 	"run findfdt; " \
-	"run envboot; " \
-	"run mmcboot;" \
-	"run emmc_linux_boot; " \
+	"run finduuid; " \
+	"run distro_bootcmd;" \
 	"run emmc_android_boot; " \
 	""
 
+#define BOOT_TARGET_DEVICES(func) \
+	func(MMC, mmc, 0) \
+	func(MMC, mmc, 1) \
+	func(PXE, pxe, na) \
+	func(DHCP, dhcp, na)
+
+#include <config_distro_bootcmd.h>
 
 #define CONFIG_EXTRA_ENV_SETTINGS \
 	DEFAULT_LINUX_BOOT_ENV \
@@ -294,6 +292,7 @@
 	DFUARGS \
 	NETARGS \
 	NANDARGS \
+	BOOTENV
 
 /*
  * SPL related defines.  The Public RAM memory map the ROM defines the