ld: Move Solaris/sparcv9 TEXT_START_ADDR to elf64_sparc_sol2.sh

While looking at the Solaris versions of the program header p_vaddr and
p_align values of the text and data segments, I noticed that the
Solaris/sparcv9 version of TEXT_START_ADDR is defined in a shared file.
Since there's a Solaris/sparcv9 specific file now
(ld/emulparams/elf64_sparc_sol2.sh), it seems cleaner to move it there.

Tested on {sparcv9,sparc}-sun-solaris2.11 and
{sparc64,sparc}-unknown-linux-gnu.

2025-07-29  Rainer Orth  <ro@CeBiTec.Uni-Bielefeld.DE>

	ld:
	* emulparams/elf64_sparc.sh (TEXT_START_ADDR): Move ...
	* emulparams/elf64_sparc_sol2.sh (TEXT_START_ADDR): ... here.