mfd: Fix compile for twl-core.c by removing cpu_is_omap usage

Commit 7d7e1eba (ARM: OMAP2+: Prepare for irqs.h removal) broke
compile for non-omap as include plat/cpu.h was added. This header
was indirectly included earlier when SPARSE_IRQ was not set, but
does not exist on most platforms.

Fix the problem by removing the cpu_is_omap usage that should
not exist in drivers at all. We can do this by adding proper
clock aliases for the twl-core.c drivers, and drop separate
handling for cases when clock framework is not available as
the behaviour will stay the same.

Note that we need to add a platform device to avoid using the
i2c provided names that may be different on various omaps.

Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Paul Walmsley <paul@pwsan.com>
Acked-by: Samuel Ortiz <sameo@linux.intel.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Cc: Olof Johansson <olof@lixom.net>
Cc: Felipe Balbi <balbi@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
diff --git a/arch/arm/mach-omap2/clock2430_data.c b/arch/arm/mach-omap2/clock2430_data.c
index 02fe1f2..7ea9139 100644
--- a/arch/arm/mach-omap2/clock2430_data.c
+++ b/arch/arm/mach-omap2/clock2430_data.c
@@ -1856,6 +1856,7 @@
 	CLK(NULL,	"func_32k_ck",	&func_32k_ck,	CK_243X),
 	CLK(NULL,	"secure_32k_ck", &secure_32k_ck, CK_243X),
 	CLK(NULL,	"osc_ck",	&osc_ck,	CK_243X),
+	CLK("twl",	"fck",		&osc_ck,	CK_243X),
 	CLK(NULL,	"sys_ck",	&sys_ck,	CK_243X),
 	CLK(NULL,	"alt_ck",	&alt_ck,	CK_243X),
 	CLK(NULL,	"mcbsp_clks",	&mcbsp_clks,	CK_243X),
diff --git a/arch/arm/mach-omap2/clock3xxx_data.c b/arch/arm/mach-omap2/clock3xxx_data.c
index 10a2398..700317a 100644
--- a/arch/arm/mach-omap2/clock3xxx_data.c
+++ b/arch/arm/mach-omap2/clock3xxx_data.c
@@ -3226,6 +3226,7 @@
 	CLK(NULL,	"virt_26000000_ck",	&virt_26000000_ck,	CK_3XXX),
 	CLK(NULL,	"virt_38_4m_ck", &virt_38_4m_ck, CK_3XXX),
 	CLK(NULL,	"osc_sys_ck",	&osc_sys_ck,	CK_3XXX),
+	CLK("twl",	"fck",		&osc_sys_ck,	CK_3XXX),
 	CLK(NULL,	"sys_ck",	&sys_ck,	CK_3XXX),
 	CLK(NULL,	"sys_altclk",	&sys_altclk,	CK_3XXX),
 	CLK(NULL,	"mcbsp_clks",	&mcbsp_clks,	CK_3XXX),