Disable ratelimiting of /dev/kmsg logs.

This is the only place that init logs to on early startup. Having the
full logs improves debugging by a lot.

The default rate limit to /dev/kmsg appears to be 5 messages per second
on average with a burst of 10.

Bug: 129989984
Change-Id: Iae7dcf022524131700d64bcc46aaba8902a0422b
Test: Build and run locally, observe ~/cuttlefish_runtime/kernel.log
diff --git a/shared/BoardConfig.mk b/shared/BoardConfig.mk
index 13274af..4cb2d75 100644
--- a/shared/BoardConfig.mk
+++ b/shared/BoardConfig.mk
@@ -147,3 +147,7 @@
 else
 TARGET_RECOVERY_FSTAB := device/google/cuttlefish/shared/config/fstab.initrd
 endif
+
+# To see full logs from init, disable ratelimiting.
+# The default is 5 messages per second amortized, with a burst of up to 10.
+BOARD_KERNEL_CMDLINE += printk.devkmsg=on