soc: pil-msa: Add module parameter to force crash system

Add support to trigger a system ramdump in cases when modem boot receives
errors from MBA. In order to enable doing so, the module parameter
"modem_trigger_panic", which could be passed from command line or set via
the sysfs node, should be set to a magic value "0XAABADEAD", before
triggering a modem boot.

Change-Id: Ic048928c3a38d5c5351afe682603e48d8b7202a5
Signed-off-by: Taniya Das <tdas@codeaurora.org>