clk: msm: clock-osm: remove ioremaps from panic callback

Calling ioremap() in clk_osm_panic_callback() can result in
BUG() when the kernel is panic-ing. It is not safe to use
ioremap() in atomic context. Map the debug registers at probe
time instead.

CRs-Fixed: 1086427
Change-Id: Ie14be6ee9ffbcb09009d5d05235e20f6ac215fa0
Signed-off-by: Osvaldo Banuelos <osvaldob@codeaurora.org>