ACPICA: Add FADT error message for GAS BitWidth overflow

Error for possible overflow during conversion from 32-bit legacy
register addresses to GAS format. The GAS struct contains a
one-byte BitWidth field, meaning that the maximum length of a
register is 255 bits. ACPICA BZ 953.

https://www.acpica.org/bugzilla/show_bug.cgi?id=953

Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>