MIPS: IP22/IP28 Disable early printk to fix boot problems on some systems.

Some Debian users have reported that the kernel hangs early during boot on
some IP22 systems. Thomas Bogendoerfer found that this is due to a "bad
interaction between CONFIG_EARLY_PRINTK and overwritten prom memory during
early boot". Since there's no fix yet, disable CONFIG_EARLY_PRINTK for now.

Signed-off-by: Martin Michlmayr <[e-mail]>
Cc: [e-mail]
Cc: Thomas Bogendoerfer <[e-mail]>
Cc: Dmitri Vorobiev <[e-mail]>
Patchwork: http://patchwork.linux-mips.org/patch/702/
Signed-off-by: Ralf Baechle <[e-mail]>

arch/mips/Kconfig

···
 	select SWAP_IO_SPACE
 	select SYS_HAS_CPU_R4X00
 	select SYS_HAS_CPU_R5000
-	select SYS_HAS_EARLY_PRINTK
+	#
+	# Disable EARLY_PRINTK for now since it leads to overwritten prom
+	# memory during early boot on some machines.
+	#
+	# See http://www.linux-mips.org/cgi-bin/mesg.cgi?a=linux-mips&i=20091119164009.GA15038%40deprecation.cyrius.com
+	# for a more details discussion
+	#
+	# select SYS_HAS_EARLY_PRINTK
 	select SYS_SUPPORTS_32BIT_KERNEL
 	select SYS_SUPPORTS_64BIT_KERNEL
 	select SYS_SUPPORTS_BIG_ENDIAN
···
 	select SGI_HAS_ZILOG
 	select SWAP_IO_SPACE
 	select SYS_HAS_CPU_R10000
-	select SYS_HAS_EARLY_PRINTK
+	#
+	# Disable EARLY_PRINTK for now since it leads to overwritten prom
+	# memory during early boot on some machines.
+	#
+	# See http://www.linux-mips.org/cgi-bin/mesg.cgi?a=linux-mips&i=20091119164009.GA15038%40deprecation.cyrius.com
+	# for a more details discussion
+	#
+	# select SYS_HAS_EARLY_PRINTK
 	select SYS_SUPPORTS_64BIT_KERNEL
 	select SYS_SUPPORTS_BIG_ENDIAN
       help