T3X: rtos_sdk add t3x board bc302, bc309 and sky [1/1]

PD#SWPL-116654

Problem:
rtos_sdk t3x board is only t3x_skt.

Solution:
rtos_sdk add t3x board bc302,bc309 and sky, delete t3x_skt.

Verify:
local build pass.

Change-Id: I00055919223293cc6758d10fe2b4f7625a97d2fb
Signed-off-by: bangzheng.liu <bangzheng.liu@amlogic.com>
diff --git a/build_combination.in b/build_combination.in
index ccacc00..f971b3e 100644
--- a/build_combination.in
+++ b/build_combination.in
@@ -2,7 +2,9 @@
 riscv a4 ba409_a113l2 aocpu
 riscv a5 av400_a113x2 aocpu
 riscv a5 av409_a113x2 aocpu
-riscv t3x t3x_skt aocpu
+riscv t3x t3x_sky aocpu
+riscv t3x bc302_t968d4 aocpu
+riscv t3x bc309_t968d4 aocpu
 riscv t5d am301_t950d4 aocpu
 riscv t5w at301_t962d4 aocpu
 riscv t5w at309_t962d4 aocpu