ARM: socfpga: remove unused CONFIG option and cleanup README.socfpga

CONFIG_SOCFPGA_DWMMC_FIFO_DEPTH is defined in the socfpga_common.h,
but not referenced at all.  Remove.

Also, clean-up the README.socfpga.  CONFIG_MMC should not be defined
in the header since it was moved to Kconfig by commit c2726995
("mmc: complete unfinished move of CONFIG_MMC").  I see no grep hit
for the others.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: NMarek Vasut <marex@denx.de>

doc/README.socfpga

@@ -14,12 +14,6 @@ socfpga_dw_mmc
 Here are macro and detailed configuration required to enable DesignWare SDMMC
 controller support within SOCFPGA
 
-#define CONFIG_MMC
--> To enable the SD MMC framework support
-
-#define CONFIG_SDMMC_BASE		(SOCFPGA_SDMMC_ADDRESS)
--> The base address of CSR register for DesignWare SDMMC controller
-
 #define CONFIG_GENERIC_MMC
 -> Enable the generic MMC driver
 
@@ -31,23 +25,3 @@ controller support within SOCFPGA
 
 #define CONFIG_SOCFPGA_DWMMC
 -> Enable the SOCFPGA specific driver for DesignWare SDMMC controller
-
-#define CONFIG_SOCFPGA_DWMMC_FIFO_DEPTH		1024
--> The FIFO depth for SOCFPGA DesignWare SDMMC controller
-
-#define CONFIG_SOCFPGA_DWMMC_DRVSEL	3
--> Phase-shifted clock of sdmmc_clk for controller to drive command and data to
-the card to meet hold time requirements. SD clock is running at 50MHz and
-drvsel is set to shift 135 degrees (3 * 45 degrees). With that, the hold time
-is 135 / 360 * 20ns = 7.5ns.
-
-#define CONFIG_SOCFPGA_DWMMC_SMPSEL	0
--> Phase-shifted clock of sdmmc_clk used to sample the command and data from
-the card
-
-#define CONFIG_SOCFPGA_DWMMC_BUS_WIDTH	4
--> Bus width of data line which either 1, 4 or 8 and based on board routing.
-
-#define CONFIG_SOCFPGA_DWMMC_BUS_HZ	50000000
--> The clock rate to controller. Do note the controller have a wrapper which
-divide the clock from PLL by 4.

include/configs/socfpga_common.h

@@ -146,7 +146,6 @@
 #define CONFIG_GENERIC_MMC
 #define CONFIG_DWMMC
 #define CONFIG_SOCFPGA_DWMMC
-#define CONFIG_SOCFPGA_DWMMC_FIFO_DEPTH	1024
 /* FIXME */
 /* using smaller max blk cnt to avoid flooding the limited stack we have */
 #define CONFIG_SYS_MMC_MAX_BLK_COUNT	256	/* FIXME -- SPL only? */