include/drivers/flash: correction on the unrestricted alignment of wr…

…ites

Telling that all the driver supports unaligned writes was and
is not true. Drivers only have to support any source buffer.

This fix message introduced by #23628

Signed-off-by: Andrzej Puzdrowski <andrzej.puzdrowski@nordicsemi.no>

include/drivers/flash.h

@@ -133,8 +133,9 @@ static inline int z_impl_flash_read(const struct device *dev, off_t offset,
  *  @brief  Write buffer into flash memory.
  *
  *  All flash drivers support a source buffer located either in RAM or
- *  SoC flash, without alignment restrictions on the source address, or
- *  write size or offset.
+ *  SoC flash, without alignment restrictions on the source address.
+ *  Write size and offset must be multiples of the minimum write block size
+ *  supported by the driver.
  *
  *  Prior to the invocation of this API, the flash_write_protection_set needs
  *  to be called first to disable the write protection.