MIPS: introduce MIPS_L1_CACHE_SHIFT_<N>

In order to avoid keeping an ever growing list of chips which need to
select a specific MIPS_L1_CACHE_SHIFT value introduce multiple internal
and non-exposed Kconfig symbols for the various MIPS_L1_CACHE_SHIFT
values out there and update the relevant Kconfig symbols to select them.

Signed-off-by: Florian Fainelli <florian@openwrt.org>
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 3d9f9a8..664c997 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -182,6 +182,7 @@
 	select SYS_SUPPORTS_128HZ
 	select SYS_SUPPORTS_256HZ
 	select SYS_SUPPORTS_1024HZ
+	select MIPS_L1_CACHE_SHIFT_4
 	help
 	  This enables support for DEC's MIPS based workstations.  For details
 	  see the Linux/MIPS FAQ on <http://www.linux-mips.org/> and the
@@ -467,6 +468,7 @@
 	select SYS_SUPPORTS_32BIT_KERNEL
 	select SYS_SUPPORTS_64BIT_KERNEL
 	select SYS_SUPPORTS_BIG_ENDIAN
+	select MIPS_L1_CACHE_SHIFT_7
 	help
 	  This are the SGI Indy, Challenge S and Indigo2, as well as certain
 	  OEM variants like the Tandem CMN B006S. To compile a Linux kernel
@@ -487,6 +489,7 @@
 	select SYS_SUPPORTS_BIG_ENDIAN
 	select SYS_SUPPORTS_NUMA
 	select SYS_SUPPORTS_SMP
+	select MIPS_L1_CACHE_SHIFT_7
 	help
 	  This are the SGI Origin 200, Origin 2000 and Onyx 2 Graphics
 	  workstations.  To compile a Linux kernel that runs on these, say Y
@@ -693,6 +696,7 @@
 	select SWAP_IO_SPACE
 	select BOOT_RAW
 	select ARCH_REQUIRE_GPIOLIB
+	select MIPS_L1_CACHE_SHIFT_4
 	help
 	  Support the Mikrotik(tm) RouterBoard 532 series,
 	  based on the IDT RC32434 SoC.
@@ -1092,6 +1096,18 @@
 config BOOT_ELF32
 	bool
 
+config MIPS_L1_CACHE_SHIFT_4
+	bool
+
+config MIPS_L1_CACHE_SHIFT_5
+	bool
+
+config MIPS_L1_CACHE_SHIFT_6
+	bool
+
+config MIPS_L1_CACHE_SHIFT_7
+	bool
+
 config MIPS_L1_CACHE_SHIFT
 	int
 	default "4" if MACH_DECSTATION || MIKROTIK_RB532 || PMC_MSP4200_EVAL || SOC_RT288X
@@ -1376,6 +1392,8 @@
 	select LIBFDT
 	select USE_OF
 	select USB_EHCI_BIG_ENDIAN_MMIO
+	select SYS_HAS_DMA_OPS
+	select MIPS_L1_CACHE_SHIFT_7
 	help
 	  The Cavium Octeon processor is a highly integrated chip containing
 	  many ethernet hardware widgets for networking tasks. The processor
@@ -1798,6 +1816,7 @@
 config MIPS_CPU_SCACHE
 	bool
 	select BOARD_SCACHE
+	select MIPS_L1_CACHE_SHIFT_6
 
 config R5000_CPU_SCACHE
 	bool