arm: socfpga: imply/default common config options

This commit moves common config options used in all socfpga boards
to select/imply in Kconfig. This both cleans up the defconfig files
as well as makes future changes easier.

Options implied/defaulted for all sub-arches:
- SPL, SPL_DM, USE_TINY_PRINTF, NR_DRAM_BANKS

Options implied/defaulted for implied for A10 & gen5:
- FPGA_SOCFPGA, SYS_MALLOC_F_LEN, SYS_TEXT_BASE

Options implied/defaulted for gen5:
- SPL_STACK_R, SPL_SYS_MALLOC_SIMPLE, SPL_STACK_R_ADDR

Signed-off-by: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>
Acked-by: Marek Vasut <marex@denx.de>

arch/arm/Kconfig

@@ -839,6 +839,8 @@ config ARCH_SOCFPGA
 	imply DM_SPI
 	imply DM_SPI_FLASH
 	imply FAT_WRITE
+	imply SPL
+	imply SPL_DM
 	imply SPL_LIBDISK_SUPPORT
 	imply SPL_MMC_SUPPORT
 	imply SYS_MMCSD_RAW_MODE_U_BOOT_USE_PARTITION

arch/arm/mach-socfpga/Kconfig

@@ -1,8 +1,22 @@
 if ARCH_SOCFPGA
 
+config NR_DRAM_BANKS
+	default 1
+
+config SPL_STACK_R_ADDR
+	default 0x00800000 if TARGET_SOCFPGA_GEN5
+
 config SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION_TYPE
 	default 0xa2
 
+config SYS_MALLOC_F_LEN
+	default 0x2000 if TARGET_SOCFPGA_ARRIA10
+	default 0x2000 if TARGET_SOCFPGA_GEN5
+
+config SYS_TEXT_BASE
+	default 0x01000040 if TARGET_SOCFPGA_ARRIA10
+	default 0x01000040 if TARGET_SOCFPGA_GEN5
+
 config TARGET_SOCFPGA_ARRIA5
 	bool
 	select TARGET_SOCFPGA_GEN5
@@ -21,6 +35,8 @@ config TARGET_SOCFPGA_ARRIA10
 	select SYSCON
 	select SPL_SYSCON if SPL
 	select ETH_DESIGNWARE_SOCFPGA
+	imply FPGA_SOCFPGA
+	imply USE_TINY_PRINTF
 
 config TARGET_SOCFPGA_CYCLONE5
 	bool
@@ -29,6 +45,10 @@ config TARGET_SOCFPGA_CYCLONE5
 config TARGET_SOCFPGA_GEN5
 	bool
 	select ALTERA_SDRAM
+	imply FPGA_SOCFPGA
+	imply SPL_STACK_R
+	imply SPL_SYS_MALLOC_SIMPLE
+	imply USE_TINY_PRINTF
 
 config TARGET_SOCFPGA_STRATIX10
 	bool