src: Remove blank acpi_tables source files

Due to build rules, dummy acpi_tables source files were added in many
mainboards. With commit - 1e83e5c61a3aa98f58f7d8cbf8d1eb9532896cc3
("src/arch/x86: Build mainboard acpi_tables source if present"),
the build system will build mainboard acpi_tables only if present. Remove
the dummy/empty/blank acpi_tables source files.

BUG=None
TEST=Build test with some google mainboards.

Signed-off-by: Karthikeyan Ramasubramanian <kramasub@google.com>
Change-Id: I0cef34368e2e5f5e3b946b22658ca10c7caad90a
---
D src/mainboard/amd/gardenia/acpi_tables.c
D src/mainboard/amd/padmelon/acpi_tables.c
D src/mainboard/apple/macbookair4_2/acpi_tables.c
D src/mainboard/asrock/h110m/acpi_tables.c
D src/mainboard/facebook/monolith/acpi_tables.c
D src/mainboard/google/dragonegg/acpi_tables.c
D src/mainboard/google/drallion/acpi_tables.c
D src/mainboard/google/eve/acpi_tables.c
D src/mainboard/google/fizz/acpi_tables.c
D src/mainboard/google/glados/acpi_tables.c
D src/mainboard/google/hatch/acpi_tables.c
D src/mainboard/google/kahlee/acpi_tables.c
D src/mainboard/google/octopus/acpi_tables.c
D src/mainboard/google/poppy/acpi_tables.c
D src/mainboard/google/reef/acpi_tables.c
D src/mainboard/google/sarien/acpi_tables.c
D src/mainboard/intel/apollolake_rvp/acpi_tables.c
D src/mainboard/intel/cannonlake_rvp/acpi_tables.c
D src/mainboard/intel/coffeelake_rvp/acpi_tables.c
D src/mainboard/intel/glkrvp/acpi_tables.c
D src/mainboard/intel/icelake_rvp/acpi_tables.c
D src/mainboard/intel/kblrvp/acpi_tables.c
D src/mainboard/intel/kunimitsu/acpi_tables.c
D src/mainboard/intel/leafhill/acpi_tables.c
D src/mainboard/intel/minnow3/acpi_tables.c
D src/mainboard/intel/saddlebrook/acpi_tables.c
D src/mainboard/purism/librem_skl/acpi_tables.c
D src/mainboard/razer/blade_stealth_kbl/acpi_tables.c
D src/mainboard/siemens/mc_apl1/acpi_tables.c
D src/mainboard/supermicro/x11-lga1151-series/acpi_tables.c
D src/mainboard/up/squared/acpi_tables.c
31 files changed, 0 insertions(+), 93 deletions(-)