sf: Divide spi_flash into multiple parts

Divided the spi_flash framework into mutiple parts for
- spi_flash.c:
        spi flash core file, interaction for spi/qspi driver to
        spi_flash framework.
- spi_flash_ops.c
        spi flash preffered operations, erase,write and read.
- spi_flash_probe.c
        spi flash probing, easy to extend probing functionality.

This change will support to extend the functionality in a
proper manner.

Signed-off-by: Jagannadha Sutradharudu Teki <jaganna@xilinx.com>
diff --git a/drivers/mtd/spi/Makefile b/drivers/mtd/spi/Makefile
index 191138a..193cb5d 100644
--- a/drivers/mtd/spi/Makefile
+++ b/drivers/mtd/spi/Makefile
@@ -14,7 +14,7 @@
 COBJS-$(CONFIG_SPL_SPI_BOOT)	+= fsl_espi_spl.o
 endif
 
-COBJS-$(CONFIG_SPI_FLASH)	+= spi_flash.o
+COBJS-$(CONFIG_SPI_FLASH)	+= spi_flash_probe.o spi_flash_ops.o spi_flash.o
 COBJS-$(CONFIG_SPI_FLASH_ATMEL)	+= atmel.o
 COBJS-$(CONFIG_SPI_FLASH_EON)	+= eon.o
 COBJS-$(CONFIG_SPI_FLASH_GIGADEVICE)	+= gigadevice.o