Drop many cases of .previous directive use

Since most assembly files are no longer concatenated together
but built separately, section changes with .previous at the
end of the files have become spurious.

TEST=BUILD_TIMELESS

Change-Id: I2970eed2b114a53475ba385eec4e97bb7ae7095c
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/47963
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>

src/cpu/intel/fit/fit.S

@@ -6,7 +6,6 @@
 fit_pointer:
 .long fit_table
 .long 0
-.previous
 
 .section .text
 .align 16
@@ -29,4 +28,3 @@ fit_table:
 .byte 0x7d
 .fill CONFIG_CPU_INTEL_NUM_FIT_ENTRIES*16
 fit_table_end:
-.previous