release_android: fix tiboot3 gp copy to aosp

tiboot3.bin (the GP variant) is never copied to aosp because the gp variable is never true. In fact $1 is for ti_out and $3 is the config file.

Use $3 to fix the problem.

Fixes: 28fc14e3 ("config: add secure.gp config entry") Signed-off-by: Mattijs Korpershoek mkorpershoek@baylibre.com

/cc @glaroque