am335x_evm: Switch to using imply keyword

These particular SPL options are part of what the ROM provides, but for
compatibility with how we have previously used them, move them to being
implied by the board being selected.

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/arch/arm/mach-omap2/am33xx/Kconfig b/arch/arm/mach-omap2/am33xx/Kconfig
index 5b5d3f8..5adcead 100644
--- a/arch/arm/mach-omap2/am33xx/Kconfig
+++ b/arch/arm/mach-omap2/am33xx/Kconfig
@@ -15,6 +15,9 @@
 	select DM_SERIAL
 	select DM_GPIO
 	select TI_I2C_BOARD_DETECT
+	imply SPL_YMODEM_SUPPORT
+	imply SPL_ENV_SUPPORT
+	imply SPL_WATCHDOG_SUPPORT
 	help
 	  This option specifies support for the AM335x
 	  GP and HS EVM development platforms. The AM335x