mtd: spi-nor: sst: Fix write enable before AAI sequence

mtd: spi-nor: sst: Fix write enable before AAI sequence

When writing to SST flash starting at an odd address, a single byte is
first programmed using the byte program (BP) command. After this
operation completes, the flash hardware automatically clears the Write
Enable Latch (WEL) bit.

If an AAI (Auto Address Increment) word program sequence follows, it
requires WEL to be set. Without re-enabling writes, the AAI sequence
fails.

Add spi_nor_write_enable() after the odd-address byte program when more
data needs to be written. Use a local boolean for clarity.

Fixes: b199489d37b2 ("mtd: spi-nor: add the framework for SPI NOR")
Cc: stable@vger.kernel.org
Signed-off-by: Sanjaikumar V S <sanjaikumar.vs@dicortech.com>
Tested-by: Hendrik Donner <hd@os-cillation.de>
Reviewed-by: Hendrik Donner <hd@os-cillation.de>
Signed-off-by: Pratyush Yadav (Google) <pratyush@kernel.org>