configs: at91: sam9x60: Switch to new reset driver

Since commit 61040097a9d1 ("reset: at91: Add reset driver for basic
assert/deassert operations") the compatible "microchip,sam9x60-rstc" for
the sam9x60 reset controller in sam9x60.dtsi is not handled by
CONFIG_SYSRESET_AT91 anymore, but by CONFIG_RESET_AT91 now.  This
resulted in the following error message, when trying to reset from
U-Boot shell:

    U-Boot> reset
    resetting ...
    System reset not supported on this platform
    ### ERROR ### Please RESET the board ###

Fixed by enabling the new driver in the relevant defconfigs.  Tested on
sam9x60-curiosity board.  Defconfigs for sam9x60ek adapted in the same
way, but without testing.  These should be all sam9x60 boards affected
in U-Boot here.

Signed-off-by: Alexander Dahl <ada@thorsis.com>
diff --git a/configs/sam9x60ek_nandflash_defconfig b/configs/sam9x60ek_nandflash_defconfig
index c6c4686..569b4e7 100644
--- a/configs/sam9x60ek_nandflash_defconfig
+++ b/configs/sam9x60ek_nandflash_defconfig
@@ -14,6 +14,7 @@
 CONFIG_DEFAULT_DEVICE_TREE="sam9x60ek"
 CONFIG_SYS_PROMPT="U-Boot> "
 CONFIG_OF_LIBFDT_OVERLAY=y
+CONFIG_DM_RESET=y
 CONFIG_DEBUG_UART_BASE=0xfffff200
 CONFIG_DEBUG_UART_CLOCK=200000000
 CONFIG_DEBUG_UART_BOARD_INIT=y
@@ -89,6 +90,7 @@
 CONFIG_MACB=y
 CONFIG_PINCTRL=y
 CONFIG_PINCTRL_AT91=y
+CONFIG_RESET_AT91=y
 CONFIG_DM_SERIAL=y
 CONFIG_DEBUG_UART_ANNOUNCE=y
 CONFIG_ATMEL_USART=y