arm: imx: hab: Add hab_failsafe console command

hab_failsafe when called puts the part into BootROM recovery mode.
This will allow u-boot scripts to script the dropping down into recovery
mode.

=> hab_failsafe

Shows the i.MX7 appear as "hiddev0,hidraw5: USB HID v1.10 Device [Freescale
SemiConductor Inc  SP Blank ULT1] " in a Linux dmesg thus allowing download
of a new image via the BootROM USB download protocol routine.

Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Cc: Stefano Babic <sbabic@denx.de>
Cc: Fabio Estevam <fabio.estevam@nxp.com>
Cc: Peng Fan <peng.fan@nxp.com>
Cc: Albert Aribaud <albert.u.boot@aribaud.net>
Cc: Sven Ebenfeld <sven.ebenfeld@gmail.com>
Cc: George McCollister <george.mccollister@gmail.com>
Cc: Breno Matheus Lima <brenomatheus@gmail.com>
Tested-by: Breno Lima <breno.lima@nxp.com>
Reviewed-by: Fabio Estevam <fabio.estevam@nxp.com>

arch/arm/mach-imx/hab.c

@@ -414,6 +414,22 @@ static int do_authenticate_image(cmd_tbl_t *cmdtp, int flag, int argc,
 	return rcode;
 }
 
+static int do_hab_failsafe(cmd_tbl_t *cmdtp, int flag, int argc,
+			   char * const argv[])
+{
+	hab_rvt_failsafe_t *hab_rvt_failsafe;
+
+	if (argc != 1) {
+		cmd_usage(cmdtp);
+		return 1;
+	}
+
+	hab_rvt_failsafe = hab_rvt_failsafe_p;
+	hab_rvt_failsafe();
+
+	return 0;
+}
+
 U_BOOT_CMD(
 		hab_status, CONFIG_SYS_MAXARGS, 1, do_hab_status,
 		"display HAB status",
@@ -429,6 +445,11 @@ U_BOOT_CMD(
 		"ivt_offset - hex offset of IVT in the image"
 	  );
 
+U_BOOT_CMD(
+		hab_failsafe, CONFIG_SYS_MAXARGS, 1, do_hab_failsafe,
+		"run BootROM failsafe routine",
+		""
+	  );
 
 #endif /* !defined(CONFIG_SPL_BUILD) */