configs: am64x_evm_*_defconfig: Increase offsets for eMMC raw boot

EMMC boot can fail due to the size of R5 SPL image growing beyond the
500KB of memory allocated in eMMC. Update offsets for eMMMC raw boot
to load each binary from the correct address in eMMC according to the
following eMMC layout:

            boot0/1 partition
    0x0+----------------------------------+
       |     tiboot3.bin (1 MB)           |
  0x800+----------------------------------+
       |       tispl.bin (2 MB)           |
0x1800+-----------------------------------+
       |       u-boot.img (4 MB)          |
0x3800+-----------------------------------+
       |      environment (128 KB)        |
0x3900+-----------------------------------+

Signed-off-by: Judith Mendez <jm@ti.com>
diff --git a/configs/am64x_evm_a53_defconfig b/configs/am64x_evm_a53_defconfig
index 8b0ccba..e000549 100644
--- a/configs/am64x_evm_a53_defconfig
+++ b/configs/am64x_evm_a53_defconfig
@@ -44,7 +44,7 @@
 CONFIG_SPL_SYS_MALLOC=y
 CONFIG_SPL_SYS_MALLOC_SIZE=0x800000
 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_USE_SECTOR=y
-CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR=0x1400
+CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR=0x1800
 CONFIG_SPL_DMA=y
 CONFIG_SPL_ENV_SUPPORT=y
 CONFIG_SPL_ETH=y