lib: Always read SPD sources as text file

Under some circumstances grep detects the input of a spd hex file
as binary resulting in an spd source not beeing added to the
resulting spd.bin. This appears to be especially the case with
heavily commented files.

This commit forces grep to read the input as text file.

Example SPD that would else be detected as binary (regardless
of stripped zero blocks).

```hex
\# TotalBytes: 512 ; BytesUsed: 384
23
\# SPD Revision 1.1
11
\# DDR Ramtype: LPDDR4X
11
\# Config Rest
0E 16 21 95 08 00 00 00 00 0A 22 00 00 49 00 04
0F 92 54 05 00 84 00 90 A8 90 C0 08 60 04 00 00
[...]
\# CRC Is: 0x1EB4 Calculated: 0x1EB4 Match!
1E B4
\# ModuleSpecificParameter
[...]
\# HybridMemoryParameter
[...]
\# ExtendedFunctionParameter
[...]
\# ManufactoringInformation
\## Module Manufactoring ID
00 00
\## Module Manufactoring Location and Date
00 00 00
\## Module Manufactoring Serial
00 00 00 00
\## Module Manufactoring Part Number: "K4UBE3D4AA-MGCL"
4B 34 55 42 45 33 44 34 41 41 2D 4D 47 43 4C 00
00 00 00 00
\## Module Manufactoring Revision Code
00
\## Module Manufactor: "Samsung" (0xCE80)
CE 80
\## Module Stepping
00
\## Module Manufactoring Data
[..]
\## Module Reserved
00 00
\# EndUserProgrammable
[...]
```

Thanks to Patrick Georgi for checking that this grep option
is widely available.

Change-Id: I7e5bad069531630b36dc3702c8c4bd94ba0946c1
Signed-off-by: Johanna Schander <coreboot@mimoja.de>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/38426
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

0 files changed, 0 insertions, 0 deletions