libgomp: Prototype "accel" 'GOMP_INDIRECT_ADDR_MAP', 'GOMP_INDIRECT_ADDR_HMAP' in 'target-indirect.h'

..., instead of repeating 'extern' prototypes in all "accel" 'team.c' files
for 'GOMP_INDIRECT_ADDR_MAP' vs. no prototype for 'GOMP_INDIRECT_ADDR_HMAP',
as done in commit da5803c794d16deb461c93588461856fbf6e54ac
"libgomp: Init hash table for 'indirect'-clause of 'declare target' on the host [PR114445, PR119857]".

	libgomp/
	* config/accel/target-indirect.h (GOMP_INDIRECT_ADDR_MAP)
	(GOMP_INDIRECT_ADDR_HMAP): Prototype.
	* config/gcn/team.c: Adjust.
	* config/nvptx/team.c: Likewise.