staging: ram_console: Fix section mismatches

WARNING: vmlinux.o(.text+0xfcf6e): Section mismatch in reference
from the function ram_console_driver_probe() to the function
.init.text:persistent_ram_init_ringbuffer()
The function ram_console_driver_probe() references
the function __init persistent_ram_init_ringbuffer().
This is often because ram_console_driver_probe lacks a __init
annotation or the annotation of persistent_ram_init_ringbuffer is
wrong.

Move this driver to platform_driver_probe() because ram console
devices aren't going to be added and removed at runtime. Also
shorten the probe function name since driver is redundant and
makes the function name long.

Cc: Android Kernel Team <kernel-team@android.com>
Cc: John Stultz <john.stultz@linaro.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Change-Id: I7d7ab806dcc3ca0ae2407e22fd50ff2e592f77e8