build: Merge default-by-family into by-variant

Prefix the BSP family name with "bsps/" to make it distinct to the BSP
variant names.

Update #4468.

spec/build/bsps/arm/imx/abi.yml

@@ -12,7 +12,6 @@ default:
 - -mfpu=neon
 - -mfloat-abi=hard
 - -mtune=cortex-a7
-default-by-family: []
 default-by-variant: []
 description: |
   ABI flags

spec/build/bsps/arm/imx/optcachedata.yml

@@ -6,7 +6,6 @@ build-type: option
 copyrights:
 - Copyright (C) 2020 embedded brains GmbH (http://www.embedded-brains.de)
 default: true
-default-by-family: []
 default-by-variant:
 - value: false
   variants:

spec/build/bsps/arm/imx/optcacheinst.yml

@@ -6,7 +6,6 @@ build-type: option
 copyrights:
 - Copyright (C) 2020 embedded brains GmbH (http://www.embedded-brains.de)
 default: true
-default-by-family: []
 default-by-variant:
 - value: false
   variants:

spec/build/bsps/arm/imx/optccmahb.yml

@@ -6,7 +6,6 @@ build-type: option
 copyrights:
 - Copyright (C) 2020 embedded brains GmbH (http://www.embedded-brains.de)
 default: 135000000
-default-by-family: []
 default-by-variant: []
 description: |
   AHB clock frequency in Hz

spec/build/bsps/arm/imx/optcmmecspi.yml

@@ -6,7 +6,6 @@ build-type: option
 copyrights:
 - Copyright (C) 2020 embedded brains GmbH (http://www.embedded-brains.de)
 default: 67500000
-default-by-family: []
 default-by-variant: []
 description: |
   ECSPI clock frequency in Hz

spec/build/bsps/arm/imx/optcmmipg.yml

@@ -6,7 +6,6 @@ build-type: option
 copyrights:
 - Copyright (C) 2020 embedded brains GmbH (http://www.embedded-brains.de)
 default: 67500000
-default-by-family: []
 default-by-variant: []
 description: |
   IPG clock frequency in Hz

spec/build/bsps/arm/imx/optcmmsdhci.yml

@@ -6,7 +6,6 @@ build-type: option
 copyrights:
 - Copyright (C) 2020 embedded brains GmbH (http://www.embedded-brains.de)
 default: 196363000
-default-by-family: []
 default-by-variant: []
 description: |
   SDHCI clock frequency in Hz

spec/build/bsps/arm/imx/optcmmuart.yml

@@ -6,7 +6,6 @@ build-type: option
 copyrights:
 - Copyright (C) 2020 embedded brains GmbH (http://www.embedded-brains.de)
 default: 24000000
-default-by-family: []
 default-by-variant: []
 description: |
   UART clock frequency in Hz

spec/build/bsps/arm/imx/optconirq.yml

@@ -6,7 +6,6 @@ build-type: option
 copyrights:
 - Copyright (C) 2020 embedded brains GmbH (http://www.embedded-brains.de)
 default: 1
-default-by-family: []
 default-by-variant: []
 description: |
   use interrupt driven mode for console devices (used by default)

spec/build/bsps/arm/imx/optresetvec.yml

@@ -6,7 +6,6 @@ build-type: option
 copyrights:
 - Copyright (C) 2020 embedded brains GmbH (http://www.embedded-brains.de)
 default: false
-default-by-family: []
 default-by-variant: []
 description: |
   reset vector address for BSP start