serial: apbuart: Fixup apbuart_console_init()

commit 35c64e5d (drivers: serial: apbuart: Handle OF failures
gracefully) missed that the modified grlib_apbuart_configure()
function is called from apbuart_console_init() as well.

Fix the fallout.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>