ARM: dts: at91: rename sama7g5ek.dts to at91-sama7g5ek.dts

In Linux this DT file is named at91-sama7g5ek.dts. Rename it accordingly.

Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
Reviewed-by: Tudor Ambarus <tudor.ambarus@microchip.com>
diff --git a/configs/sama7g5ek_mmc_defconfig b/configs/sama7g5ek_mmc_defconfig
index 6891baa..7bbe656 100644
--- a/configs/sama7g5ek_mmc_defconfig
+++ b/configs/sama7g5ek_mmc_defconfig
@@ -8,7 +8,7 @@
 CONFIG_SYS_MEMTEST_END=0x70000000
 CONFIG_ENV_SIZE=0x4000
 CONFIG_DM_GPIO=y
-CONFIG_DEFAULT_DEVICE_TREE="sama7g5ek"
+CONFIG_DEFAULT_DEVICE_TREE="at91-sama7g5ek"
 CONFIG_DEBUG_UART_BOARD_INIT=y
 CONFIG_DEBUG_UART_BASE=0xe1824200
 CONFIG_DEBUG_UART_CLOCK=200000000