spi: spi-mtk-nor: initialize spi controller after resume

After system resumes, the registers of nor controller are
initialized with default values. The nor controller will
not function properly.

To handle both issues above, we add mtk_nor_init() in
mtk_nor_resume after pm_runtime_force_resume().

Fixes: 3bfd9103

 ("spi: spi-mtk-nor: Add power management support")

Signed-off-by: Allen-KH Cheng <allen-kh.cheng@mediatek.com>
Reviewed-by: Rex-BC Chen <rex-bc.chen@mediatek.com>
Link: https://lore.kernel.org/r/20220412115743.22641-1-allen-kh.cheng@mediatek.com
Signed-off-by: Mark Brown <broonie@kernel.org>