sf: Remove spansion_s25fss_disable_4KB_erase

sf: Remove spansion_s25fss_disable_4KB_erase

In spansion S25FS-S family the physical sectors are grouped as
normal and parameter sectors. Parameter sectors are 4kB in size
with 8 set located at the bottom or top address of a device.
Normal sectors are similar to other flash family with sizes of
64kB or 32 kB.

To erase whole flash using sector erase(D8h or DCh) won't effect
the parameter sectors, so in order to erase these we must use 4K
sector erase commands (20h or 21h) separately.

So better to erase the whole flash using 4K sector erase instead
of detecting these family parts again and do two different erase
operations.

For this:
- Removed spansion_s25fss_disable_4KB_erase code
- Add SECT_4K for S25FS512S chip

Cc: Yunhui Cui <yunhui.cui@nxp.com>
Cc: Bin Meng <bmeng.cn@gmail.com>
Cc: York Sun <york.sun@nxp.com>
Cc: Vignesh R <vigneshr@ti.com>
Cc: Mugunthan V N <mugunthanvnm@ti.com>
Cc: Michal Simek <michal.simek@xilinx.com>
Cc: Michael Trimarchi <michael@amarulasolutions.com>
Cc: Siva Durga Prasad Paladugu <sivadur@xilinx.com>
Signed-off-by: Jagan Teki <jagan@openedev.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Jagan Teki <jagan@openedev.com>
Tested-by: Jagan Teki <jagan@openedev.com>