platform/x86: intel_pmc_core: update TGL's LPM0 reg bit map name

PMC debug tools use lpm0's 23rd bit to reflect Main PLL, not just
Audio PLL. So, update tgl_lpm0 debug reg bit map name.

Signed-off-by: Sathyanarayana Nujella <sathyanarayana.nujella@intel.com>
Signed-off-by: Arava Jairaj <jairaj.arava@intel.com>
Acked-by: David E. Box <david.e.box@intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>