spi-nor: intel-spi: Remove the unnecessary HSFSTS register RW

There is no code that alters the HSFSTS register content in between
in intel_spi_write(). Remove the unnecessary RW to save some cycles.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Cyrille Pitchen <cyrille.pitchen@wedev4u.fr>