phy: convert swphy register generation to tabular form

Convert the swphy register generation to tabular form which allows us
to eliminate multiple switch() statements.  This results in a smaller
object code size, more efficient, and easier to add support for faster
speeds.

Before:

Idx Name          Size      VMA       LMA       File off  Algn
  0 .text         00000164  00000000  00000000  00000034  2**2

   text    data     bss     dec     hex filename
    388       0       0     388     184 swphy.o

After:

Idx Name          Size      VMA       LMA       File off  Algn
  0 .text         000000fc  00000000  00000000  00000034  2**2
  5 .rodata       00000028  00000000  00000000  00000138  2**2

   text    data     bss     dec     hex filename
    324       0       0     324     144 swphy.o

Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>