ARM: da850-evm: Remove references to CONFIG_DA850_AM18X_EVM

With the removal of da850_am18xxevm, there is at least one
whitelisted CONFIG option that can be deleted.  This patch
removes CONFIG_DA850_AM18X_EVM since it's not required any more

Signed-off-by: Adam Ford <aford173@gmail.com>
diff --git a/board/davinci/da8xxevm/da850evm.c b/board/davinci/da8xxevm/da850evm.c
index fcf9334..f04392e 100644
--- a/board/davinci/da8xxevm/da850evm.c
+++ b/board/davinci/da8xxevm/da850evm.c
@@ -300,9 +300,6 @@
 		rev = 2;
 	else if (maxcpuclk >= 372000000)
 		rev = 1;
-#ifdef CONFIG_DA850_AM18X_EVM
-	rev |= REV_AM18X_EVM;
-#endif
 	return rev;
 }
 
diff --git a/scripts/config_whitelist.txt b/scripts/config_whitelist.txt
index 89119ae..85f75a4 100644
--- a/scripts/config_whitelist.txt
+++ b/scripts/config_whitelist.txt
@@ -280,7 +280,6 @@
 CONFIG_CTL_TBE
 CONFIG_CUSTOMER_BOARD_SUPPORT
 CONFIG_D2NET_V2
-CONFIG_DA850_AM18X_EVM
 CONFIG_DA850_EVM_MAX_CPU_CLK
 CONFIG_DBGU
 CONFIG_DB_784MP_GP