Early printk has been removed already that's why also remove calling it.
Similar change has been done in cpuinfo-pvr-full.c by commit cfbd8d19
("microblaze: Remove early printk setup").

Fixes: 96f0e6fc ("microblaze: remove redundant early_printk support")
Signed-off-by: Michal Simek <michal.simek@amd.com>
Link: https://lore.kernel.org/r/2f10db506be8188fa07b6ec331caca01af1b10f8.1712824039.git.michal.simek@amd.com