Rename ECAM-specific MMCONF Kconfigs

Currently, the MMCONF Kconfigs only support the Enhanced Configuration
Access mechanism (ECAM) method for accessing the PCI config address
space.  Some platforms have a different way of mapping the PCI config
space to memory.  This patch renames the following configs to
make it clear that these configs are ECAM-specific:

- NO_MMCONF_SUPPORT --> NO_ECAM_MMCONF_SUPPORT
- MMCONF_SUPPORT --> ECAM_MMCONF_SUPPORT
- MMCONF_BASE_ADDRESS --> ECAM_MMCONF_BASE_ADDRESS
- MMCONF_BUS_NUMBER --> ECAM_MMCONF_BUS_NUMBER
- MMCONF_LENGTH --> ECAM_MMCONF_LENGTH

Please refer to CB:57861 "Proposed coreboot Changes" for more
details.

BUG=b:181098581
BRANCH=None
TEST=./util/abuild/abuild -p none -t GOOGLE_KOHAKU -x -a -c max
     Make sure Jenkins verifies that builds on other boards

Change-Id: I1e196a1ed52d131a71f00cba1d93a23e54aca3e2
Signed-off-by: Shelley Chen <shchen@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/57333
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>

src/soc/example/min86/Kconfig

@@ -16,7 +16,7 @@ config SOC_SPECIFIC_OPTIONS
 	def_bool y
 	select ARCH_X86
 	select NO_MONOTONIC_TIMER
-	select NO_MMCONF_SUPPORT
+	select NO_ECAM_MMCONF_SUPPORT
 	select UNKNOWN_TSC_RATE
 
 config DCACHE_BSP_STACK_SIZE		# required by arch/x86/car.ld