This patch fixes the following compilation error when including
`release/uart16550.c` into the module test.
./release/uart16550.c:14:6: error: conflicting types for ‘get_pio_dbg_uart_cfg’; have ‘bool(uint64_t *, uint64_t *)’ {aka ‘_Bool(long unsigned int *, long unsigned int *)’}
14 | bool get_pio_dbg_uart_cfg(__unused uint64_t *pio_address, __unused uint64_t *nbytes) {
| ^~~~~~~~~~~~~~~~~~~~
./include/debug/uart16550.h:142:6: note: previous declaration of ‘get_pio_dbg_uart_cfg’ with type ‘bool(uint16_t *, uint32_t *)’ {aka ‘_Bool(short unsigned int *, unsigned int *)’}
142 | bool get_pio_dbg_uart_cfg(uint16_t *pio_address, uint32_t *nbytes);
| ^~~~~~~~~~~~~~~~~~~~
Tracked-On: #861
Signed-off-by: Gao, Shiqing <shiqing.gao@intel.com>