kernel: fix earlycon by keeping __earlycon_table

Somewhere between 4.4 and 4.9 there was a change that made
OF_EARLYCON_DECLARE adding entries to the __earlycon_table instead of
__earlycon_of_table. We need to keep this table as well.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>

target/linux/generic/patches-4.9/220-gc_sections.patch

@@ -63,6 +63,15 @@ Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
  			 VMLINUX_SYMBOL(__stop_syscalls_metadata) = .;
  #else
  #define TRACE_SYSCALLS()
+@@ -156,7 +156,7 @@
+ #ifdef CONFIG_SERIAL_EARLYCON
+ #define EARLYCON_TABLE() STRUCT_ALIGN();			\
+ 			 VMLINUX_SYMBOL(__earlycon_table) = .;	\
+-			 *(__earlycon_table)			\
++			 KEEP(*(__earlycon_table))		\
+ 			 VMLINUX_SYMBOL(__earlycon_table_end) = .;
+ #else
+ #define EARLYCON_TABLE()
 @@ -169,8 +169,8 @@
  #define _OF_TABLE_1(name)						\
  	. = ALIGN(8);							\

target/linux/generic/patches-4.9/721-phy_packets.patch

@@ -28,7 +28,7 @@
  	const struct header_ops *header_ops;
  
  	unsigned int		flags;
-@@ -1779,6 +1782,10 @@ struct net_device {
+@@ -1779,6 +1786,10 @@ struct net_device {
  	struct mpls_dev __rcu	*mpls_ptr;
  #endif