soc: aspeed: socinfo: Add AST2625 variant

Add AST26XX series AST2625-A3 SOC ID, taken from the vendor u-boot SDK:

 arch/arm/mach-aspeed/ast2600/scu_info.c
 +       SOC_ID("AST2625-A3", 0x0503040305030403),

Reviewed-by: Dylan Hung <dylan_hung@aspeedtech.com>
Link: https://lore.kernel.org/r/20210818010534.2508122-1-joel@jms.id.au


Signed-off-by: Joel Stanley <joel@jms.id.au>