configs: rpi: set NR_DRAM_BANKS to four

With the new RPi4 which has 8 GB of RAM, we can have up to four DRAM
banks. Bump up the configuration files to detect all the memory in
U-Boot.
Signed-off-by: NMatthias Brugger <mbrugger@suse.com>

configs/rpi_4_32b_defconfig

@@ -4,7 +4,7 @@ CONFIG_SYS_TEXT_BASE=0x00008000
 CONFIG_TARGET_RPI_4_32B=y
 CONFIG_SYS_MALLOC_F_LEN=0x2000
 CONFIG_ENV_SIZE=0x4000
-CONFIG_NR_DRAM_BANKS=2
+CONFIG_NR_DRAM_BANKS=4
 CONFIG_DISTRO_DEFAULTS=y
 CONFIG_OF_BOARD_SETUP=y
 CONFIG_ARCH_FIXUP_FDT_MEMORY=y

configs/rpi_4_defconfig

@@ -4,7 +4,7 @@ CONFIG_SYS_TEXT_BASE=0x00080000
 CONFIG_TARGET_RPI_4=y
 CONFIG_SYS_MALLOC_F_LEN=0x2000
 CONFIG_ENV_SIZE=0x4000
-CONFIG_NR_DRAM_BANKS=2
+CONFIG_NR_DRAM_BANKS=4
 CONFIG_DISTRO_DEFAULTS=y
 CONFIG_OF_BOARD_SETUP=y
 CONFIG_ARCH_FIXUP_FDT_MEMORY=y

configs/rpi_arm64_defconfig

@@ -4,7 +4,7 @@ CONFIG_SYS_TEXT_BASE=0x00080000
 CONFIG_TARGET_RPI_ARM64=y
 CONFIG_SYS_MALLOC_F_LEN=0x2000
 CONFIG_ENV_SIZE=0x4000
-CONFIG_NR_DRAM_BANKS=2
+CONFIG_NR_DRAM_BANKS=4
 CONFIG_DISTRO_DEFAULTS=y
 CONFIG_OF_BOARD_SETUP=y
 CONFIG_USE_PREBOOT=y