docs: Remove ast2700fc from Aspeed family boards

The ast2700fc machine is now covered in the dedicated ast2700-evb
section. Listing it in the general Aspeed board family list is
redundant.

Signed-off-by: Steven Lee <steven_lee@aspeedtech.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Link: https://lore.kernel.org/qemu-devel/20250523093144.991408-7-steven_lee@aspeedtech.com
Signed-off-by: Cédric Le Goater <clg@redhat.com>

docs/system/arm/aspeed.rst

@@ -1,4 +1,4 @@
-Aspeed family boards (``ast2500-evb``, ``ast2600-evb``, ``ast2700-evb``, ``ast2700fc``, ``bletchley-bmc``, ``fuji-bmc``, ``fby35-bmc``, ``fp5280g2-bmc``, ``g220a-bmc``, ``palmetto-bmc``, ``qcom-dc-scm-v1-bmc``, ``qcom-firework-bmc``, ``quanta-q71l-bmc``, ``rainier-bmc``, ``romulus-bmc``, ``sonorapass-bmc``, ``supermicrox11-bmc``, ``supermicrox11spi-bmc``, ``tiogapass-bmc``, ``witherspoon-bmc``, ``yosemitev2-bmc``)
+Aspeed family boards (``ast2500-evb``, ``ast2600-evb``, ``ast2700-evb``, ``bletchley-bmc``, ``fuji-bmc``, ``fby35-bmc``, ``fp5280g2-bmc``, ``g220a-bmc``, ``palmetto-bmc``, ``qcom-dc-scm-v1-bmc``, ``qcom-firework-bmc``, ``quanta-q71l-bmc``, ``rainier-bmc``, ``romulus-bmc``, ``sonorapass-bmc``, ``supermicrox11-bmc``, ``supermicrox11spi-bmc``, ``tiogapass-bmc``, ``witherspoon-bmc``, ``yosemitev2-bmc``)
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 The QEMU Aspeed machines model BMCs of various OpenPOWER systems and