microblaze: cache: introduce Kconfig options for icache/dcache sizes

Replace XILINX_DCACHE_BYTE_SIZE macro with two Kconfig symbols for
instruction and data caches sizes, respectively:
CONFIG_XILINX_MICROBLAZE0_ICACHE_SIZE
CONFIG_XILINX_MICROBLAZE0_DCACHE_SIZE

Also, get rid of the hardcoded value in icache_disable().

Signed-off-by: Ovidiu Panait <ovpanait@gmail.com>
Link: https://lore.kernel.org/r/20220531181435.3473549-8-ovpanait@gmail.com
Signed-off-by: Michal Simek <michal.simek@amd.com> (s/bralid/brlid/g)
diff --git a/board/xilinx/microblaze-generic/Kconfig b/board/xilinx/microblaze-generic/Kconfig
index 98b4814..a6743ca 100644
--- a/board/xilinx/microblaze-generic/Kconfig
+++ b/board/xilinx/microblaze-generic/Kconfig
@@ -85,4 +85,20 @@
 	bool
 	default XILINX_MICROBLAZE0_USE_WIC
 
+config XILINX_MICROBLAZE0_DCACHE_SIZE
+	int "Default data cache size"
+	default 32768
+	help
+	  This fallback size will be used when no dcache info can be found in
+	  the device tree, or when the data cache is flushed very early in the
+	  boot process, before device tree is available.
+
+config XILINX_MICROBLAZE0_ICACHE_SIZE
+	int "Default instruction cache size"
+	default 32768
+	help
+	  This fallback size will be used when no icache info can be found in
+	  the device tree, or when the instruction cache is flushed very early
+	  in the boot process, before device tree is available.
+
 endif