linux/export: fix reference to exported functions for parisc64

linux/export: fix reference to exported functions for parisc64

John David Anglin reported parisc has been broken since commit
ddb5cdbafaaa ("kbuild: generate KSYMTAB entries by modpost").

Like ia64, parisc64 uses a function descriptor. The function
references must be prefixed with P%.

Also, symbols prefixed $$ from the library have the symbol type
STT_LOPROC instead of STT_FUNC. They should be handled as functions
too.

Fixes: ddb5cdbafaaa ("kbuild: generate KSYMTAB entries by modpost")
Reported-by: John David Anglin <[email protected]>
Tested-by: John David Anglin <[email protected]>
Tested-by: Helge Deller <[email protected]>
Closes: https://lore.kernel.org/linux-parisc/[email protected]/T/#u
Signed-off-by: Masahiro Yamada <[email protected]>
Signed-off-by: Helge Deller <[email protected]>