Refactor linker-generated arrays

Refactor linker-generated array code so that symbols
which were previously linker-generated are now compiler-
generated. This causes relocation records of type
R_ARM_ABS32 to become R_ARM_RELATIVE, which makes
code which uses LGA able to run before relocation as
well as after.

Note: this affects more than ARM targets, as linker-
lists span possibly all target architectures, notably
PowerPC.

Conflicts:
	arch/arm/cpu/arm926ejs/mxs/u-boot-spl.lds
	arch/arm/cpu/arm926ejs/spear/u-boot-spl.lds
	arch/arm/cpu/armv7/omap-common/u-boot-spl.lds
	board/ait/cam_enc_4xx/u-boot-spl.lds
	board/davinci/da8xxevm/u-boot-spl-da850evm.lds
	board/davinci/da8xxevm/u-boot-spl-hawk.lds
	board/vpac270/u-boot-spl.lds

Signed-off-by: Albert ARIBAUD <albert.u.boot@aribaud.net>