TXHD2: PXP Bringup Bootloader BL30 code portinig [2/3]

PD#SWPL-117323

Problem:
TXHD2 PXP Bringup Bootloader BL30.

Solution:
Code porting from T5D, S5 and ucode.
Add TXHD2 skt compile.

Verify:
Test in z1.

Change-Id: I913d14de192594cede2f9831128f875bddcea53f
Signed-off-by: bangzheng.liu <bangzheng.liu@amlogic.com>
diff --git a/build_combination.in b/build_combination.in
index f971b3e..efe77d5 100644
--- a/build_combination.in
+++ b/build_combination.in
@@ -10,6 +10,7 @@
 riscv t5w at309_t962d4 aocpu
 riscv t5m ay301_t963d4 aocpu
 riscv t5m ay309_t963d4 aocpu
+riscv txhd2 txhd2_skt aocpu
 riscv s5 ax201_s928x aocpu
 riscv s5 ax208_s928x aocpu
 riscv s5 ax209_s928x aocpu