printf: Remove some L modifier uses

printf: Remove some L modifier uses

We use the L modifier in a non-standard way (for
long long instead of long double, which we have no
business with).
clang complains, to reduce its use, to make
emulation/qemu-x86 happier.
Long term, we should consider eliminating public uses
of 'L' (but internal use in vtxprintf to denote
long long is fine)

Change-Id: If9a17d9ae9925cdc8736445e7d5eedc59c7028c6
Signed-off-by: Patrick Georgi <patrick@georgi-clan.de>
Reviewed-on: http://review.coreboot.org/781
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>