doc, pa: HPPA option documentation cleanup [PR122243]

doc, pa: HPPA option documentation cleanup [PR122243]

Note that the default for the -mlra option on HPPA was recently
changed from 0 to 1.  This option has never been documented for this
target and reload is supposed to be going away entirely soon, so I
see no reason to document it now.

gcc/ChangeLog
	PR other/122243
	* config/pa/pa.opt (mbig-switch): Mark obsolete option as
	"Undocumented".
	(mjump-in-delay): Likewise.
	(mlra): Likewise.
	(mnosnake, msnake): Likewise.
	* doc/invoke.texi (Option Summary) <HPPA Options>: Remove
	deliberately undocumented options from list.  Remove redundant
	negative/positive forms from list.  Fix formatting so there is
	uniformly two spaces between options on the same line.
	(HPPA Options): Remove documentation for obsolete options.
	Add @opindex for negative forms.  Properly list -mwsio instead
	of just referring to it in the -msio docs.  Light copy-editing to
	fix markup, jargon, etc.