psoc64: Add TARGET_CONFIG_HEADER_FILE

Adjust NS_AGENT_MAILBOX_STACK_SIZE up to 0xC00 as 0x800 is
not large enough for SFN backend for compilers like armclang
v6.18, gcc v7.3.1.

Signed-off-by: Sherry Zhang <sherry.zhang2@arm.com>
Change-Id: I8381a2d887ed52f51872a2979b50a19ccd15dac5
1 file changed