mb/siemens/mc_ehl2: Update SPD for DDR4 devices

Since this variant uses different DDR4 devices compared to mc_ehl1 in a
memory down configuration, the SPD data file must be adapted.
In a first configuration we use Micron MT53D512M32D2NP modules.

Following values were adjusted according to this board characteristic
and with help of Serial Presence Detect (SPD) for LPDDR3 and LPDDR4
SDRAM Modules JEDEC Spec and the Specification for this Micron modules
itself:

- SPD Byte 4 - only 4Gb density instead of 8Gb for mc_ehl1
- SPD Byte 5 - different Row and Column Address Bits
- SPD Byte 29/30 - 4Gb LPDDR4 needs 130ns tRFCab
- SPD Byte 31/32 - 4Gb LPDDR4 needs 60ns tRFCpb

Change-Id: Icb25f418952f0c96117140863d0d9c897d814ac5
Signed-off-by: Mario Scheithauer <mario.scheithauer@siemens.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/58111
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Werner Zeh <werner.zeh@siemens.com>

src/mainboard/siemens/mc_ehl/variants/mc_ehl2/spd/mc_ehl2.spd.hex

@@ -1,6 +1,6 @@
-23 11 11 0E 15 21 90 08 00 40 00 00 02 22 00 00
-00 00 04 0F 92 54 05 00 87 00 90 A8 90 C0 08 60
-04 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+23 11 11 0E 14 19 90 08 00 40 00 00 02 22 00 00
+00 00 04 0F 92 54 05 00 87 00 90 A8 90 10 04 E0
+01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00