drm/amd: Load GFX11 microcode during early_init

If GFX11 microcode is required but not available during early init, the
firmware framebuffer will have already been released and the screen will
freeze.

Move the request for GFX11 microcode into the early_init phase
so that if it's not available, driver init will fail.

Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Lijo Lazar <lijo.lazar@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>